17 files changed, 3080 insertions, 0 deletions
diff --git a/rendy-memory/Cargo.toml b/rendy-memory/Cargo.toml
new file mode 100644
index 0000000..8a0d29f
--- /dev/null
+++ b/rendy-memory/Cargo.toml
@@ -0,0 +1,27 @@
+[package]
+name = "rendy-memory"
+version = "0.5.3"
+authors = ["omni-viral <scareaangel@gmail.com>"]
+edition = "2018"
+repository = "https://github.com/amethyst/rendy"
+license = "MIT OR Apache-2.0"
+documentation = "https://docs.rs/rendy-memory"
+keywords = ["graphics", "gfx-hal", "rendy"]
+categories = ["rendering"]
+description = "Rendy's memory manager"
+
+[features]
+serde-1 = ["serde", "gfx-hal/serde"]
+
+[dependencies]
+gfx-hal = "^0.8"
+log = "0.4.11"
+hibitset = { version = "0.6.3", default-features = false }
+relevant = { version = "0.4.2", features = ["log"] }
+serde = { version = "1.0.118", optional = true, features = ["derive"] }
+smallvec = "1.5.1"
+slab = "0.4.2"
+colorful = "0.2.1"
+
+[dev-dependencies]
+rand = "0.8.0"
diff --git a/rendy-memory/src/allocator/dedicated.rs b/rendy-memory/src/allocator/dedicated.rs
new file mode 100644
index 0000000..7806509
--- /dev/null
+++ b/rendy-memory/src/allocator/dedicated.rs
@@ -0,0 +1,218 @@
+use std::{ops::Range, ptr::NonNull};
+
+use {
+    crate::{
+        allocator::{Allocator, Kind},
+        block::Block,
+        mapping::{mapped_sub_range, MappedRange},
+        memory::*,
+        util::*,
+    },
+    gfx_hal::{device::Device as _, Backend},
+};
+
+/// Memory block allocated from `DedicatedAllocator`
+#[derive(Debug)]
+pub struct DedicatedBlock<B: Backend> {
+    memory: Memory<B>,
+    mapping: Option<(NonNull<u8>, Range<u64>)>,
+}
+
+unsafe impl<B> Send for DedicatedBlock<B> where B: Backend {}
+unsafe impl<B> Sync for DedicatedBlock<B> where B: Backend {}
+
+impl<B> DedicatedBlock<B>
+where
+    B: Backend,
+{
+    /// Get inner memory.
+    /// Panics if mapped.
+    pub fn unwrap_memory(self) -> Memory<B> {
+        assert!(self.mapping.is_none());
+        self.memory
+    }
+
+    /// Make unmapped block.
+    pub fn from_memory(memory: Memory<B>) -> Self {
+        DedicatedBlock {
+            memory,
+            mapping: None,
+        }
+    }
+}
+
+impl<B> Block<B> for DedicatedBlock<B>
+where
+    B: Backend,
+{
+    #[inline]
+    fn properties(&self) -> gfx_hal::memory::Properties {
+        self.memory.properties()
+    }
+
+    #[inline]
+    fn memory(&self) -> &B::Memory {
+        self.memory.raw()
+    }
+
+    #[inline]
+    fn range(&self) -> Range<u64> {
+        0..self.memory.size()
+    }
+
+    fn map<'a>(
+        &'a mut self,
+        device: &B::Device,
+        range: Range<u64>,
+    ) -> Result<MappedRange<'a, B>, gfx_hal::device::MapError> {
+        assert!(
+            range.start < range.end,
+            "Memory mapping region must have valid size"
+        );
+
+        if !self.memory.host_visible() {
+            //TODO: invalid access error
+            return Err(gfx_hal::device::MapError::MappingFailed);
+        }
+
+        let requested_range = range.clone();
+        let mapping_range = if !self.memory.host_coherent() {
+            align_range(range, self.memory.non_coherent_atom_size())
+        } else {
+            range
+        };
+
+        unsafe {
+            if let Some(ptr) = self
+                .mapping
+                .clone()
+                .and_then(|(ptr, range)| mapped_sub_range(ptr, range, mapping_range.clone()))
+            {
+                Ok(MappedRange::from_raw(
+                    &self.memory,
+                    ptr,
+                    mapping_range,
+                    requested_range,
+                ))
+            } else {
+                self.unmap(device);
+                let ptr = device.map_memory(
+                    self.memory.raw_mut(),
+                    gfx_hal::memory::Segment {
+                        offset: mapping_range.start,
+                        size: Some(mapping_range.end - mapping_range.start),
+                    },
+                )?;
+                let ptr = NonNull::new(ptr).expect("Memory mapping shouldn't return nullptr");
+                let mapping =
+                    MappedRange::from_raw(&self.memory, ptr, mapping_range, requested_range);
+                self.mapping = Some((mapping.ptr(), mapping.range()));
+                Ok(mapping)
+            }
+        }
+    }
+
+    fn unmap(&mut self, device: &B::Device) {
+        if self.mapping.take().is_some() {
+            unsafe {
+                // trace!("Unmap memory: {:#?}", self.memory);
+                device.unmap_memory(self.memory.raw_mut());
+            }
+        }
+    }
+}
+
+/// Dedicated memory allocator that uses memory object per allocation requested.
+///
+/// This allocator suites best huge allocations.
+/// From 32 MiB when GPU has 4-8 GiB memory total.
+///
+/// `Heaps` use this allocator when none of sub-allocators bound to the memory type
+/// can handle size required.
+/// TODO: Check if resource prefers dedicated memory.
+#[derive(Debug)]
+pub struct DedicatedAllocator {
+    memory_type: gfx_hal::MemoryTypeId,
+    memory_properties: gfx_hal::memory::Properties,
+    non_coherent_atom_size: u64,
+    used: u64,
+}
+
+impl DedicatedAllocator {
+    /// Get properties required by the allocator.
+    pub fn properties_required() -> gfx_hal::memory::Properties {
+        gfx_hal::memory::Properties::empty()
+    }
+
+    /// Create new `LinearAllocator`
+    /// for `memory_type` with `memory_properties` specified
+    pub fn new(
+        memory_type: gfx_hal::MemoryTypeId,
+        memory_properties: gfx_hal::memory::Properties,
+        non_coherent_atom_size: u64,
+    ) -> Self {
+        DedicatedAllocator {
+            memory_type,
+            memory_properties,
+            non_coherent_atom_size,
+            used: 0,
+        }
+    }
+}
+
+impl<B> Allocator<B> for DedicatedAllocator
+where
+    B: Backend,
+{
+    type Block = DedicatedBlock<B>;
+
+    fn kind() -> Kind {
+        Kind::Dedicated
+    }
+
+    #[inline]
+    fn alloc(
+        &mut self,
+        device: &B::Device,
+        size: u64,
+        _align: u64,
+    ) -> Result<(DedicatedBlock<B>, u64), gfx_hal::device::AllocationError> {
+        let size = if is_non_coherent_visible(self.memory_properties) {
+            align_size(size, self.non_coherent_atom_size)
+        } else {
+            size
+        };
+
+        let memory = unsafe {
+            Memory::from_raw(
+                device.allocate_memory(self.memory_type, size)?,
+                size,
+                self.memory_properties,
+                self.non_coherent_atom_size,
+            )
+        };
+
+        self.used += size;
+
+        Ok((DedicatedBlock::from_memory(memory), size))
+    }
+
+    #[inline]
+    fn free(&mut self, device: &B::Device, mut block: DedicatedBlock<B>) -> u64 {
+        block.unmap(device);
+        let size = block.memory.size();
+        self.used -= size;
+        unsafe {
+            device.free_memory(block.memory.into_raw());
+        }
+        size
+    }
+}
+
+impl Drop for DedicatedAllocator {
+    fn drop(&mut self) {
+        if self.used > 0 {
+            log::error!("Not all allocation from DedicatedAllocator was freed");
+        }
+    }
+}
diff --git a/rendy-memory/src/allocator/dynamic.rs b/rendy-memory/src/allocator/dynamic.rs
new file mode 100644
index 0000000..a41cc27
--- /dev/null
+++ b/rendy-memory/src/allocator/dynamic.rs
@@ -0,0 +1,716 @@
+use std::{
+    collections::{BTreeSet, HashMap},
+    ops::Range,
+    ptr::NonNull,
+    thread,
+};
+
+use {
+    crate::{
+        allocator::{Allocator, Kind},
+        block::Block,
+        mapping::*,
+        memory::*,
+        util::*,
+    },
+    gfx_hal::{device::Device as _, Backend},
+    hibitset::{BitSet, BitSetLike as _},
+};
+
+/// Memory block allocated from `DynamicAllocator`
+#[derive(Debug)]
+pub struct DynamicBlock<B: Backend> {
+    block_index: u32,
+    chunk_index: u32,
+    count: u32,
+    memory: *const Memory<B>,
+    ptr: Option<NonNull<u8>>,
+    range: Range<u64>,
+    relevant: relevant::Relevant,
+}
+
+unsafe impl<B> Send for DynamicBlock<B> where B: Backend {}
+unsafe impl<B> Sync for DynamicBlock<B> where B: Backend {}
+
+impl<B> DynamicBlock<B>
+where
+    B: Backend,
+{
+    fn shared_memory(&self) -> &Memory<B> {
+        // Memory won't be freed until last block created from it deallocated.
+        unsafe { &*self.memory }
+    }
+
+    fn size(&self) -> u64 {
+        self.range.end - self.range.start
+    }
+
+    fn dispose(self) {
+        self.relevant.dispose();
+    }
+}
+
+impl<B> Block<B> for DynamicBlock<B>
+where
+    B: Backend,
+{
+    #[inline]
+    fn properties(&self) -> gfx_hal::memory::Properties {
+        self.shared_memory().properties()
+    }
+
+    #[inline]
+    fn memory(&self) -> &B::Memory {
+        self.shared_memory().raw()
+    }
+
+    #[inline]
+    fn range(&self) -> Range<u64> {
+        self.range.clone()
+    }
+
+    #[inline]
+    fn map<'a>(
+        &'a mut self,
+        _device: &B::Device,
+        range: Range<u64>,
+    ) -> Result<MappedRange<'a, B>, gfx_hal::device::MapError> {
+        debug_assert!(
+            range.start < range.end,
+            "Memory mapping region must have valid size"
+        );
+
+        if !self.shared_memory().host_visible() {
+            //TODO: invalid access error
+            return Err(gfx_hal::device::MapError::MappingFailed);
+        }
+
+        let requested_range = relative_to_sub_range(self.range.clone(), range)
+            .ok_or(gfx_hal::device::MapError::OutOfBounds)?;
+
+        let mapping_range = if !self.shared_memory().host_coherent() {
+            align_range(
+                requested_range.clone(),
+                self.shared_memory().non_coherent_atom_size(),
+            )
+        } else {
+            requested_range.clone()
+        };
+
+        if let Some(ptr) = self.ptr {
+            let ptr = mapped_sub_range(ptr, self.range.clone(), mapping_range.clone()).unwrap();
+            let mapping = unsafe {
+                MappedRange::from_raw(self.shared_memory(), ptr, mapping_range, requested_range)
+            };
+            Ok(mapping)
+        } else {
+            Err(gfx_hal::device::MapError::MappingFailed)
+        }
+    }
+
+    #[inline]
+    fn unmap(&mut self, _device: &B::Device) {}
+}
+
+/// Config for `DynamicAllocator`.
+#[derive(Clone, Copy, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct DynamicConfig {
+    /// All requests are rounded up to multiple of this value.
+    pub block_size_granularity: u64,
+
+    /// Maximum chunk of blocks size.
+    /// Actual chunk size is `min(max_chunk_size, block_size * blocks_per_chunk)`
+    pub max_chunk_size: u64,
+
+    /// Minimum size of device allocation.
+    pub min_device_allocation: u64,
+}
+
+/// No-fragmentation allocator.
+/// Suitable for any type of small allocations.
+/// Every freed block can be reused.
+#[derive(Debug)]
+pub struct DynamicAllocator<B: Backend> {
+    /// Memory type that this allocator allocates.
+    memory_type: gfx_hal::MemoryTypeId,
+
+    /// Memory properties of the memory type.
+    memory_properties: gfx_hal::memory::Properties,
+
+    /// All requests are rounded up to multiple of this value.
+    block_size_granularity: u64,
+
+    /// Maximum chunk of blocks size.
+    max_chunk_size: u64,
+
+    /// Minimum size of device allocation.
+    min_device_allocation: u64,
+
+    /// Chunk lists.
+    sizes: HashMap<u64, SizeEntry<B>>,
+
+    /// Ordered set of sizes that have allocated chunks.
+    chunks: BTreeSet<u64>,
+    non_coherent_atom_size: u64,
+}
+
+unsafe impl<B> Send for DynamicAllocator<B> where B: Backend {}
+unsafe impl<B> Sync for DynamicAllocator<B> where B: Backend {}
+
+#[derive(Debug)]
+struct SizeEntry<B: Backend> {
+    /// Total count of allocated blocks with size corresponding to this entry.
+    total_blocks: u64,
+
+    /// Bits per ready (non-exhausted) chunks with free blocks.
+    ready_chunks: BitSet,
+
+    /// List of chunks.
+    chunks: slab::Slab<Chunk<B>>,
+}
+
+impl<B> Default for SizeEntry<B>
+where
+    B: Backend,
+{
+    fn default() -> Self {
+        SizeEntry {
+            chunks: Default::default(),
+            total_blocks: 0,
+            ready_chunks: Default::default(),
+        }
+    }
+}
+
+const MAX_BLOCKS_PER_CHUNK: u32 = 64;
+const MIN_BLOCKS_PER_CHUNK: u32 = 8;
+
+impl<B> DynamicAllocator<B>
+where
+    B: Backend,
+{
+    /// Create new `DynamicAllocator`
+    /// for `memory_type` with `memory_properties` specified,
+    /// with `DynamicConfig` provided.
+    pub fn new(
+        memory_type: gfx_hal::MemoryTypeId,
+        memory_properties: gfx_hal::memory::Properties,
+        config: DynamicConfig,
+        non_coherent_atom_size: u64,
+    ) -> Self {
+        log::trace!(
+            "Create new allocator: type: '{:?}', properties: '{:#?}' config: '{:#?}'",
+            memory_type,
+            memory_properties,
+            config
+        );
+
+        assert!(
+            config.block_size_granularity.is_power_of_two(),
+            "Allocation granularity must be power of two"
+        );
+
+        let block_size_granularity = if is_non_coherent_visible(memory_properties) {
+            non_coherent_atom_size
+                .max(config.block_size_granularity)
+                .next_power_of_two()
+        } else {
+            config.block_size_granularity
+        };
+
+        assert!(
+            config.max_chunk_size.is_power_of_two(),
+            "Max chunk size must be power of two"
+        );
+
+        assert!(
+            config.min_device_allocation.is_power_of_two(),
+            "Min device allocation must be power of two"
+        );
+
+        assert!(
+            config.min_device_allocation <= config.max_chunk_size,
+            "Min device allocation must be less than or equalt to max chunk size"
+        );
+
+        if memory_properties.contains(gfx_hal::memory::Properties::CPU_VISIBLE) {
+            debug_assert!(
+                fits_usize(config.max_chunk_size),
+                "Max chunk size must fit usize for mapping"
+            );
+        }
+
+        DynamicAllocator {
+            memory_type,
+            memory_properties,
+            block_size_granularity,
+            max_chunk_size: config.max_chunk_size,
+            min_device_allocation: config.min_device_allocation,
+            sizes: HashMap::new(),
+            chunks: BTreeSet::new(),
+            non_coherent_atom_size,
+        }
+    }
+
+    /// Maximum allocation size.
+    pub fn max_allocation(&self) -> u64 {
+        self.max_chunk_size / MIN_BLOCKS_PER_CHUNK as u64
+    }
+
+    /// Allocate memory chunk from device.
+    fn alloc_chunk_from_device(
+        &self,
+        device: &B::Device,
+        block_size: u64,
+        chunk_size: u64,
+    ) -> Result<Chunk<B>, gfx_hal::device::AllocationError> {
+        log::trace!(
+            "Allocate chunk of size: {} for blocks of size {} from device",
+            chunk_size,
+            block_size
+        );
+
+        // Allocate from device.
+        let (memory, mapping) = unsafe {
+            // Valid memory type specified.
+            let mut raw = device.allocate_memory(self.memory_type, chunk_size)?;
+
+            let mapping = if self
+                .memory_properties
+                .contains(gfx_hal::memory::Properties::CPU_VISIBLE)
+            {
+                log::trace!("Map new memory object");
+                match device.map_memory(
+                    &mut raw,
+                    gfx_hal::memory::Segment {
+                        offset: 0,
+                        size: Some(chunk_size),
+                    },
+                ) {
+                    Ok(mapping) => Some(NonNull::new_unchecked(mapping)),
+                    Err(gfx_hal::device::MapError::OutOfMemory(error)) => {
+                        device.free_memory(raw);
+                        return Err(error.into());
+                    }
+                    Err(_) => panic!("Unexpected mapping failure"),
+                }
+            } else {
+                None
+            };
+            let memory = Memory::from_raw(
+                raw,
+                chunk_size,
+                self.memory_properties,
+                self.non_coherent_atom_size,
+            );
+            (memory, mapping)
+        };
+        Ok(Chunk::from_memory(block_size, memory, mapping))
+    }
+
+    /// Allocate memory chunk for given block size.
+    fn alloc_chunk(
+        &mut self,
+        device: &B::Device,
+        block_size: u64,
+        total_blocks: u64,
+    ) -> Result<(Chunk<B>, u64), gfx_hal::device::AllocationError> {
+        log::trace!(
+            "Allocate chunk for blocks of size {} ({} total blocks allocated)",
+            block_size,
+            total_blocks
+        );
+
+        let min_chunk_size = MIN_BLOCKS_PER_CHUNK as u64 * block_size;
+        let min_size = min_chunk_size.min(total_blocks * block_size);
+        let max_chunk_size = MAX_BLOCKS_PER_CHUNK as u64 * block_size;
+
+        // If smallest possible chunk size is larger then this allocator max allocation
+        if min_size > self.max_allocation()
+            || (total_blocks < MIN_BLOCKS_PER_CHUNK as u64
+                && min_size >= self.min_device_allocation)
+        {
+            // Allocate memory block from device.
+            let chunk = self.alloc_chunk_from_device(device, block_size, min_size)?;
+            return Ok((chunk, min_size));
+        }
+
+        if let Some(&chunk_size) = self
+            .chunks
+            .range(min_chunk_size..=max_chunk_size)
+            .next_back()
+        {
+            // Allocate block for the chunk.
+            let (block, allocated) = self.alloc_from_entry(device, chunk_size, 1, block_size)?;
+            Ok((Chunk::from_block(block_size, block), allocated))
+        } else {
+            let total_blocks = self.sizes[&block_size].total_blocks;
+            let chunk_size =
+                (max_chunk_size.min(min_chunk_size.max(total_blocks * block_size)) / 2 + 1)
+                    .next_power_of_two();
+            let (block, allocated) = self.alloc_block(device, chunk_size, block_size)?;
+            Ok((Chunk::from_block(block_size, block), allocated))
+        }
+    }
+
+    /// Allocate blocks from particular chunk.
+    fn alloc_from_chunk(
+        chunks: &mut slab::Slab<Chunk<B>>,
+        chunk_index: u32,
+        block_size: u64,
+        count: u32,
+        align: u64,
+    ) -> Option<DynamicBlock<B>> {
+        log::trace!(
+            "Allocate {} consecutive blocks of size {} from chunk {}",
+            count,
+            block_size,
+            chunk_index
+        );
+
+        let chunk = &mut chunks[chunk_index as usize];
+        let block_index = chunk.acquire_blocks(count, block_size, align)?;
+        let block_range = chunk.blocks_range(block_size, block_index, count);
+
+        debug_assert_eq!((block_range.end - block_range.start) % count as u64, 0);
+
+        Some(DynamicBlock {
+            range: block_range.clone(),
+            memory: chunk.shared_memory(),
+            block_index,
+            chunk_index,
+            count,
+            ptr: chunk.mapping_ptr().map(|ptr| {
+                mapped_sub_range(ptr, chunk.range(), block_range)
+                    .expect("Block must be sub-range of chunk")
+            }),
+            relevant: relevant::Relevant,
+        })
+    }
+
+    /// Allocate blocks from size entry.
+    fn alloc_from_entry(
+        &mut self,
+        device: &B::Device,
+        block_size: u64,
+        count: u32,
+        align: u64,
+    ) -> Result<(DynamicBlock<B>, u64), gfx_hal::device::AllocationError> {
+        log::trace!(
+            "Allocate {} consecutive blocks for size {} from the entry",
+            count,
+            block_size
+        );
+
+        debug_assert!(count < MIN_BLOCKS_PER_CHUNK);
+        let size_entry = self.sizes.entry(block_size).or_default();
+
+        for chunk_index in (&size_entry.ready_chunks).iter() {
+            if let Some(block) = Self::alloc_from_chunk(
+                &mut size_entry.chunks,
+                chunk_index,
+                block_size,
+                count,
+                align,
+            ) {
+                return Ok((block, 0));
+            }
+        }
+
+        if size_entry.chunks.vacant_entry().key() > max_chunks_per_size() {
+            return Err(gfx_hal::device::OutOfMemory::Host.into());
+        }
+
+        let total_blocks = size_entry.total_blocks;
+        let (chunk, allocated) = self.alloc_chunk(device, block_size, total_blocks)?;
+        let size_entry = self.sizes.entry(block_size).or_default();
+        let chunk_index = size_entry.chunks.insert(chunk) as u32;
+
+        let block = Self::alloc_from_chunk(
+            &mut size_entry.chunks,
+            chunk_index,
+            block_size,
+            count,
+            align,
+        )
+        .expect("New chunk should yield blocks");
+
+        if !size_entry.chunks[chunk_index as usize].is_exhausted() {
+            size_entry.ready_chunks.add(chunk_index);
+        }
+
+        Ok((block, allocated))
+    }
+
+    /// Allocate block.
+    fn alloc_block(
+        &mut self,
+        device: &B::Device,
+        block_size: u64,
+        align: u64,
+    ) -> Result<(DynamicBlock<B>, u64), gfx_hal::device::AllocationError> {
+        log::trace!("Allocate block of size {}", block_size);
+
+        debug_assert_eq!(block_size % self.block_size_granularity, 0);
+        let size_entry = self.sizes.entry(block_size).or_default();
+        size_entry.total_blocks += 1;
+
+        let overhead = (MIN_BLOCKS_PER_CHUNK as u64 - 1) / size_entry.total_blocks;
+
+        if overhead >= 1 {
+            if let Some(&size) = self
+                .chunks
+                .range(block_size / 4..block_size * overhead)
+                .next()
+            {
+                return self.alloc_from_entry(
+                    device,
+                    size,
+                    ((block_size - 1) / size + 1) as u32,
+                    align,
+                );
+            }
+        }
+
+        if size_entry.total_blocks == MIN_BLOCKS_PER_CHUNK as u64 {
+            self.chunks.insert(block_size);
+        }
+
+        self.alloc_from_entry(device, block_size, 1, align)
+    }
+
+    fn free_chunk(&mut self, device: &B::Device, chunk: Chunk<B>, block_size: u64) -> u64 {
+        log::trace!("Free chunk: {:#?}", chunk);
+        assert!(chunk.is_unused(block_size));
+        match chunk.flavor {
+            ChunkFlavor::Dedicated(mut boxed, _) => {
+                let size = boxed.size();
+                unsafe {
+                    if self
+                        .memory_properties
+                        .contains(gfx_hal::memory::Properties::CPU_VISIBLE)
+                    {
+                        log::trace!("Unmap memory: {:#?}", boxed);
+                        device.unmap_memory(boxed.raw_mut());
+                    }
+                    device.free_memory(boxed.into_raw());
+                }
+                size
+            }
+            ChunkFlavor::Dynamic(dynamic_block) => self.free(device, dynamic_block),
+        }
+    }
+
+    fn free_block(&mut self, device: &B::Device, block: DynamicBlock<B>) -> u64 {
+        log::trace!("Free block: {:#?}", block);
+
+        let block_size = block.size() / block.count as u64;
+        let size_entry = &mut self
+            .sizes
+            .get_mut(&block_size)
+            .expect("Unable to get size entry from which block was allocated");
+        let chunk_index = block.chunk_index;
+        let chunk = &mut size_entry.chunks[chunk_index as usize];
+        let block_index = block.block_index;
+        let count = block.count;
+        block.dispose();
+        chunk.release_blocks(block_index, count);
+        if chunk.is_unused(block_size) {
+            size_entry.ready_chunks.remove(chunk_index);
+            let chunk = size_entry.chunks.remove(chunk_index as usize);
+            self.free_chunk(device, chunk, block_size)
+        } else {
+            size_entry.ready_chunks.add(chunk_index);
+            0
+        }
+    }
+
+    /// Perform full cleanup of the memory allocated.
+    pub fn dispose(self) {
+        if !thread::panicking() {
+            for (index, size) in self.sizes {
+                assert_eq!(size.chunks.len(), 0, "SizeEntry({}) is still used", index);
+            }
+        } else {
+            for (index, size) in self.sizes {
+                if !size.chunks.is_empty() {
+                    log::error!("Memory leak: SizeEntry({}) is still used", index);
+                }
+            }
+        }
+    }
+}
+
+impl<B> Allocator<B> for DynamicAllocator<B>
+where
+    B: Backend,
+{
+    type Block = DynamicBlock<B>;
+
+    fn kind() -> Kind {
+        Kind::Dynamic
+    }
+
+    fn alloc(
+        &mut self,
+        device: &B::Device,
+        size: u64,
+        align: u64,
+    ) -> Result<(DynamicBlock<B>, u64), gfx_hal::device::AllocationError> {
+        debug_assert!(size <= self.max_allocation());
+        debug_assert!(align.is_power_of_two());
+        let aligned_size = ((size - 1) | (align - 1) | (self.block_size_granularity - 1)) + 1;
+
+        // This will change nothing if `self.non_coherent_atom_size` is power of two.
+        // But just in case...
+        let aligned_size = if is_non_coherent_visible(self.memory_properties) {
+            align_size(aligned_size, self.non_coherent_atom_size)
+        } else {
+            aligned_size
+        };
+
+        log::trace!(
+            "Allocate dynamic block: size: {}, align: {}, aligned size: {}, type: {}",
+            size,
+            align,
+            aligned_size,
+            self.memory_type.0
+        );
+
+        self.alloc_block(device, aligned_size, align)
+    }
+
+    fn free(&mut self, device: &B::Device, block: DynamicBlock<B>) -> u64 {
+        self.free_block(device, block)
+    }
+}
+
+/// Block allocated for chunk.
+#[derive(Debug)]
+enum ChunkFlavor<B: Backend> {
+    /// Allocated from device.
+    Dedicated(Box<Memory<B>>, Option<NonNull<u8>>),
+
+    /// Allocated from chunk of bigger blocks.
+    Dynamic(DynamicBlock<B>),
+}
+
+#[derive(Debug)]
+struct Chunk<B: Backend> {
+    flavor: ChunkFlavor<B>,
+    blocks: u64,
+}
+
+impl<B> Chunk<B>
+where
+    B: Backend,
+{
+    fn from_memory(block_size: u64, memory: Memory<B>, mapping: Option<NonNull<u8>>) -> Self {
+        let blocks = memory.size() / block_size;
+        debug_assert!(blocks <= MAX_BLOCKS_PER_CHUNK as u64);
+
+        let high_bit = 1 << (blocks - 1);
+
+        Chunk {
+            flavor: ChunkFlavor::Dedicated(Box::new(memory), mapping),
+            blocks: (high_bit - 1) | high_bit,
+        }
+    }
+
+    fn from_block(block_size: u64, chunk_block: DynamicBlock<B>) -> Self {
+        let blocks = (chunk_block.size() / block_size).min(MAX_BLOCKS_PER_CHUNK as u64);
+
+        let high_bit = 1 << (blocks - 1);
+
+        Chunk {
+            flavor: ChunkFlavor::Dynamic(chunk_block),
+            blocks: (high_bit - 1) | high_bit,
+        }
+    }
+
+    fn shared_memory(&self) -> &Memory<B> {
+        match &self.flavor {
+            ChunkFlavor::Dedicated(boxed, _) => &*boxed,
+            ChunkFlavor::Dynamic(chunk_block) => chunk_block.shared_memory(),
+        }
+    }
+
+    fn range(&self) -> Range<u64> {
+        match &self.flavor {
+            ChunkFlavor::Dedicated(boxed, _) => 0..boxed.size(),
+            ChunkFlavor::Dynamic(chunk_block) => chunk_block.range(),
+        }
+    }
+
+    fn size(&self) -> u64 {
+        let range = self.range();
+        range.end - range.start
+    }
+
+    // Get block bytes range
+    fn blocks_range(&self, block_size: u64, block_index: u32, count: u32) -> Range<u64> {
+        let range = self.range();
+        let start = range.start + block_size * block_index as u64;
+        let end = start + block_size * count as u64;
+        debug_assert!(end <= range.end);
+        start..end
+    }
+
+    /// Check if there are free blocks.
+    fn is_unused(&self, block_size: u64) -> bool {
+        let blocks = (self.size() / block_size).min(MAX_BLOCKS_PER_CHUNK as u64);
+
+        let high_bit = 1 << (blocks - 1);
+        let mask = (high_bit - 1) | high_bit;
+
+        debug_assert!(self.blocks <= mask);
+        self.blocks == mask
+    }
+
+    /// Check if there are free blocks.
+    fn is_exhausted(&self) -> bool {
+        self.blocks == 0
+    }
+
+    fn acquire_blocks(&mut self, count: u32, block_size: u64, align: u64) -> Option<u32> {
+        debug_assert!(count > 0 && count <= MAX_BLOCKS_PER_CHUNK);
+
+        // Holds a bit-array of all positions with `count` free blocks.
+        let mut blocks = !0;
+        for i in 0..count {
+            blocks &= self.blocks >> i;
+        }
+        // Find a position in `blocks` that is aligned.
+        while blocks != 0 {
+            let index = blocks.trailing_zeros();
+            blocks &= !(1 << index);
+
+            if (index as u64 * block_size) & (align - 1) == 0 {
+                let mask = ((1 << count) - 1) << index;
+                self.blocks &= !mask;
+                return Some(index);
+            }
+        }
+        None
+    }
+
+    fn release_blocks(&mut self, index: u32, count: u32) {
+        let mask = ((1 << count) - 1) << index;
+        debug_assert_eq!(self.blocks & mask, 0);
+        self.blocks |= mask;
+    }
+
+    fn mapping_ptr(&self) -> Option<NonNull<u8>> {
+        match &self.flavor {
+            ChunkFlavor::Dedicated(_, ptr) => *ptr,
+            ChunkFlavor::Dynamic(chunk_block) => chunk_block.ptr,
+        }
+    }
+}
+
+fn max_chunks_per_size() -> usize {
+    let value = (std::mem::size_of::<usize>() * 8).pow(4);
+    debug_assert!(fits_u32(value));
+    value
+}
diff --git a/rendy-memory/src/allocator/linear.rs b/rendy-memory/src/allocator/linear.rs
new file mode 100644
index 0000000..6687d4a
--- /dev/null
+++ b/rendy-memory/src/allocator/linear.rs
@@ -0,0 +1,363 @@
+use std::{collections::VecDeque, ops::Range, ptr::NonNull};
+
+use {
+    crate::{
+        allocator::{Allocator, Kind},
+        block::Block,
+        mapping::*,
+        memory::*,
+        util::*,
+    },
+    gfx_hal::{device::Device as _, Backend},
+    std::sync::Arc,
+};
+
+/// Memory block allocated from `LinearAllocator`
+pub struct LinearBlock<B: Backend> {
+    memory: Arc<Memory<B>>,
+    linear_index: u64,
+    ptr: NonNull<u8>,
+    range: Range<u64>,
+    relevant: relevant::Relevant,
+}
+
+impl<B> std::fmt::Debug for LinearBlock<B>
+where
+    B: Backend,
+{
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        fmt.debug_struct("LinearBlock")
+            .field("memory", &*self.memory)
+            .field("linear_index", &self.linear_index)
+            .field("ptr", &self.ptr)
+            .field("range", &self.range)
+            .finish()
+    }
+}
+
+unsafe impl<B> Send for LinearBlock<B> where B: Backend {}
+unsafe impl<B> Sync for LinearBlock<B> where B: Backend {}
+
+impl<B> LinearBlock<B>
+where
+    B: Backend,
+{
+    fn size(&self) -> u64 {
+        self.range.end - self.range.start
+    }
+
+    fn dispose(self) {
+        self.relevant.dispose();
+    }
+}
+
+impl<B> Block<B> for LinearBlock<B>
+where
+    B: Backend,
+{
+    #[inline]
+    fn properties(&self) -> gfx_hal::memory::Properties {
+        self.memory.properties()
+    }
+
+    #[inline]
+    fn memory(&self) -> &B::Memory {
+        self.memory.raw()
+    }
+
+    #[inline]
+    fn range(&self) -> Range<u64> {
+        self.range.clone()
+    }
+
+    #[inline]
+    fn map<'a>(
+        &'a mut self,
+        _device: &B::Device,
+        range: Range<u64>,
+    ) -> Result<MappedRange<'a, B>, gfx_hal::device::MapError> {
+        assert!(
+            range.start < range.end,
+            "Memory mapping region must have valid size"
+        );
+
+        if !self.memory.host_visible() {
+            //TODO: invalid access error
+            return Err(gfx_hal::device::MapError::MappingFailed);
+        }
+
+        let requested_range = relative_to_sub_range(self.range.clone(), range)
+            .ok_or(gfx_hal::device::MapError::OutOfBounds)?;
+
+        let mapping_range = if !self.memory.host_coherent() {
+            align_range(
+                requested_range.clone(),
+                self.memory.non_coherent_atom_size(),
+            )
+        } else {
+            requested_range.clone()
+        };
+
+        let ptr = mapped_sub_range(self.ptr, self.range.clone(), mapping_range.clone()).unwrap();
+        let mapping =
+            unsafe { MappedRange::from_raw(&*self.memory, ptr, mapping_range, requested_range) };
+        Ok(mapping)
+    }
+
+    #[inline]
+    fn unmap(&mut self, _device: &B::Device) {
+        debug_assert!(self.memory.host_visible());
+    }
+}
+
+/// Config for `LinearAllocator`.
+#[derive(Clone, Copy, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct LinearConfig {
+    /// Size of the linear chunk.
+    /// Keep it big.
+    pub linear_size: u64,
+}
+
+/// Linear allocator that return memory from chunk sequentially.
+/// It keeps only number of bytes allocated from each chunk.
+/// Once chunk is exhausted it is placed into list.
+/// When all blocks allocated from head of that list are freed,
+/// head is freed as well.
+///
+/// This allocator suites best short-lived types of allocations.
+/// Allocation strategy requires minimal overhead and implementation is fast.
+/// But holding single block will completely stop memory recycling.
+#[derive(Debug)]
+pub struct LinearAllocator<B: Backend> {
+    memory_type: gfx_hal::MemoryTypeId,
+    memory_properties: gfx_hal::memory::Properties,
+    linear_size: u64,
+    offset: u64,
+    lines: VecDeque<Line<B>>,
+    non_coherent_atom_size: u64,
+}
+
+#[derive(Debug)]
+struct Line<B: Backend> {
+    used: u64,
+    free: u64,
+    memory: Arc<Memory<B>>,
+    ptr: NonNull<u8>,
+}
+
+unsafe impl<B> Send for Line<B> where B: Backend {}
+unsafe impl<B> Sync for Line<B> where B: Backend {}
+
+impl<B> LinearAllocator<B>
+where
+    B: Backend,
+{
+    /// Get properties required by the `LinearAllocator`.
+    pub fn properties_required() -> gfx_hal::memory::Properties {
+        gfx_hal::memory::Properties::CPU_VISIBLE
+    }
+
+    /// Maximum allocation size.
+    pub fn max_allocation(&self) -> u64 {
+        self.linear_size / 2
+    }
+
+    /// Create new `LinearAllocator`
+    /// for `memory_type` with `memory_properties` specified,
+    /// with `LinearConfig` provided.
+    pub fn new(
+        memory_type: gfx_hal::MemoryTypeId,
+        memory_properties: gfx_hal::memory::Properties,
+        config: LinearConfig,
+        non_coherent_atom_size: u64,
+    ) -> Self {
+        log::trace!(
+            "Create new 'linear' allocator: type: '{:?}', properties: '{:#?}' config: '{:#?}'",
+            memory_type,
+            memory_properties,
+            config
+        );
+        let linear_size = if is_non_coherent_visible(memory_properties) {
+            align_size(config.linear_size, non_coherent_atom_size)
+        } else {
+            config.linear_size
+        };
+        assert!(memory_properties.contains(Self::properties_required()));
+        assert!(
+            fits_usize(linear_size),
+            "Linear size must fit in both usize and u64"
+        );
+        LinearAllocator {
+            memory_type,
+            memory_properties,
+            linear_size,
+            offset: 0,
+            lines: VecDeque::new(),
+            non_coherent_atom_size,
+        }
+    }
+
+    /// Perform full cleanup of the memory allocated.
+    pub fn dispose(mut self, device: &B::Device) {
+        let _ = self.cleanup(device, 0);
+        if !self.lines.is_empty() {
+            log::error!(
+                "Lines are not empty during allocator disposal. Lines: {:#?}",
+                self.lines
+            );
+        }
+    }
+
+    fn cleanup(&mut self, device: &B::Device, off: usize) -> u64 {
+        let mut freed = 0;
+        while self.lines.len() > off {
+            if self.lines[0].used > self.lines[0].free {
+                break;
+            }
+
+            let line = self.lines.pop_front().unwrap();
+            self.offset += 1;
+
+            unsafe {
+                match Arc::try_unwrap(line.memory) {
+                    Ok(mut memory) => {
+                        // trace!("Unmap memory: {:#?}", line.memory);
+                        device.unmap_memory(memory.raw_mut());
+
+                        freed += memory.size();
+                        device.free_memory(memory.into_raw());
+                    }
+                    Err(_) => log::error!("Allocated `Line` was freed, but memory is still shared and never will be destroyed"),
+                }
+            }
+        }
+        freed
+    }
+}
+
+impl<B> Allocator<B> for LinearAllocator<B>
+where
+    B: Backend,
+{
+    type Block = LinearBlock<B>;
+
+    fn kind() -> Kind {
+        Kind::Linear
+    }
+
+    fn alloc(
+        &mut self,
+        device: &B::Device,
+        size: u64,
+        align: u64,
+    ) -> Result<(LinearBlock<B>, u64), gfx_hal::device::AllocationError> {
+        debug_assert!(self
+            .memory_properties
+            .contains(gfx_hal::memory::Properties::CPU_VISIBLE));
+
+        let (size, align) = if is_non_coherent_visible(self.memory_properties) {
+            (
+                align_size(size, self.non_coherent_atom_size),
+                align_size(align, self.non_coherent_atom_size),
+            )
+        } else {
+            (size, align)
+        };
+
+        assert!(size <= self.linear_size);
+        assert!(align <= self.linear_size);
+
+        let count = self.lines.len() as u64;
+        if let Some(line) = self.lines.back_mut() {
+            let aligned_offset = aligned(line.used, align);
+            let overhead = aligned_offset - line.used;
+            if self.linear_size - size > aligned_offset {
+                line.used = aligned_offset + size;
+                line.free += overhead;
+
+                let range = aligned_offset..aligned_offset + size;
+
+                let ptr = mapped_sub_range(line.ptr, 0..self.linear_size, range.clone())
+                    .expect("This sub-range must fit in line mapping");
+
+                return Ok((
+                    LinearBlock {
+                        linear_index: self.offset + count - 1,
+                        memory: line.memory.clone(),
+                        ptr,
+                        range,
+                        relevant: relevant::Relevant,
+                    },
+                    0,
+                ));
+            }
+        }
+
+        let (memory, ptr) = unsafe {
+            let mut raw = device.allocate_memory(self.memory_type, self.linear_size)?;
+
+            let ptr = match device.map_memory(
+                &mut raw,
+                gfx_hal::memory::Segment {
+                    offset: 0,
+                    size: Some(self.linear_size),
+                },
+            ) {
+                Ok(ptr) => NonNull::new_unchecked(ptr),
+                Err(gfx_hal::device::MapError::OutOfMemory(error)) => {
+                    device.free_memory(raw);
+                    return Err(error.into());
+                }
+                Err(_) => panic!("Unexpected mapping failure"),
+            };
+
+            let memory = Memory::from_raw(
+                raw,
+                self.linear_size,
+                self.memory_properties,
+                self.non_coherent_atom_size,
+            );
+
+            (memory, ptr)
+        };
+
+        let line = Line {
+            used: size,
+            free: 0,
+            ptr,
+            memory: Arc::new(memory),
+        };
+
+        let block = LinearBlock {
+            linear_index: self.offset + count,
+            memory: line.memory.clone(),
+            ptr,
+            range: 0..size,
+            relevant: relevant::Relevant,
+        };
+
+        self.lines.push_back(line);
+        Ok((block, self.linear_size))
+    }
+
+    fn free(&mut self, device: &B::Device, block: Self::Block) -> u64 {
+        let index = block.linear_index - self.offset;
+        assert!(
+            fits_usize(index),
+            "This can't exceed lines list length which fits into usize by definition"
+        );
+        let index = index as usize;
+        assert!(
+            index < self.lines.len(),
+            "Can't be allocated from not yet created line"
+        );
+        {
+            let line = &mut self.lines[index];
+            line.free += block.size();
+        }
+        block.dispose();
+
+        self.cleanup(device, 1)
+    }
+}
diff --git a/rendy-memory/src/allocator/mod.rs b/rendy-memory/src/allocator/mod.rs
new file mode 100644
index 0000000..770a8a8
--- /dev/null
+++ b/rendy-memory/src/allocator/mod.rs
@@ -0,0 +1,50 @@
+//! This module provides `Allocator` trait and few allocators that implements the trait.
+
+mod dedicated;
+mod dynamic;
+mod linear;
+
+use crate::block::Block;
+
+pub use self::{
+    dedicated::{DedicatedAllocator, DedicatedBlock},
+    dynamic::{DynamicAllocator, DynamicBlock, DynamicConfig},
+    linear::{LinearAllocator, LinearBlock, LinearConfig},
+};
+
+/// Allocator kind.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Kind {
+    /// Memory object per allocation.
+    Dedicated,
+
+    /// General purpose allocator.
+    Dynamic,
+
+    /// Allocates linearly.
+    /// Fast and low overhead.
+    /// Suitable for one-time-use allocations.
+    Linear,
+}
+
+/// Allocator trait implemented for various allocators.
+pub trait Allocator<B: gfx_hal::Backend> {
+    /// Block type returned by allocator.
+    type Block: Block<B>;
+
+    /// Get allocator kind.
+    fn kind() -> Kind;
+
+    /// Allocate block of memory.
+    /// On success returns allocated block and amount of memory consumed from device.
+    fn alloc(
+        &mut self,
+        device: &B::Device,
+        size: u64,
+        align: u64,
+    ) -> Result<(Self::Block, u64), gfx_hal::device::AllocationError>;
+
+    /// Free block of memory.
+    /// Returns amount of memory returned to the device.
+    fn free(&mut self, device: &B::Device, block: Self::Block) -> u64;
+}
diff --git a/rendy-memory/src/block.rs b/rendy-memory/src/block.rs
new file mode 100644
index 0000000..23ff4f4
--- /dev/null
+++ b/rendy-memory/src/block.rs
@@ -0,0 +1,36 @@
+use std::ops::Range;
+
+use crate::mapping::MappedRange;
+
+/// Block that owns a `Range` of the `Memory`.
+/// Implementor must ensure that there can't be any other blocks
+/// with overlapping range (either through type system or safety notes for unsafe functions).
+/// Provides access to safe memory range mapping.
+pub trait Block<B: gfx_hal::Backend> {
+    /// Get memory properties of the block.
+    fn properties(&self) -> gfx_hal::memory::Properties;
+
+    /// Get raw memory object.
+    fn memory(&self) -> &B::Memory;
+
+    /// Get memory range owned by this block.
+    fn range(&self) -> Range<u64>;
+
+    /// Get size of the block.
+    fn size(&self) -> u64 {
+        let range = self.range();
+        range.end - range.start
+    }
+
+    /// Get mapping for the buffer range.
+    /// Memory writes to the region performed by device become available for the host.
+    fn map<'a>(
+        &'a mut self,
+        device: &B::Device,
+        range: Range<u64>,
+    ) -> Result<MappedRange<'a, B>, gfx_hal::device::MapError>;
+
+    /// Release memory mapping. Must be called after successful `map` call.
+    /// No-op if block is not mapped.
+    fn unmap(&mut self, device: &B::Device);
+}
diff --git a/rendy-memory/src/heaps/heap.rs b/rendy-memory/src/heaps/heap.rs
new file mode 100644
index 0000000..6595cbc
--- /dev/null
+++ b/rendy-memory/src/heaps/heap.rs
@@ -0,0 +1,49 @@
+use crate::utilization::*;
+
+#[derive(Debug)]
+pub(super) struct MemoryHeap {
+    size: u64,
+    used: u64,
+    effective: u64,
+}
+
+impl MemoryHeap {
+    pub(super) fn new(size: u64) -> Self {
+        MemoryHeap {
+            size,
+            used: 0,
+            effective: 0,
+        }
+    }
+
+    pub(super) fn available(&self) -> u64 {
+        if self.used > self.size {
+            log::warn!("Heap size exceeded");
+            0
+        } else {
+            self.size - self.used
+        }
+    }
+
+    pub(super) fn allocated(&mut self, used: u64, effective: u64) {
+        self.used += used;
+        self.effective += effective;
+        debug_assert!(self.used >= self.effective);
+    }
+
+    pub(super) fn freed(&mut self, used: u64, effective: u64) {
+        self.used -= used;
+        self.effective -= effective;
+        debug_assert!(self.used >= self.effective);
+    }
+
+    pub(super) fn utilization(&self) -> MemoryHeapUtilization {
+        MemoryHeapUtilization {
+            utilization: MemoryUtilization {
+                used: self.used,
+                effective: self.effective,
+            },
+            size: self.size,
+        }
+    }
+}
diff --git a/rendy-memory/src/heaps/memory_type.rs b/rendy-memory/src/heaps/memory_type.rs
new file mode 100644
index 0000000..e3c2e72
--- /dev/null
+++ b/rendy-memory/src/heaps/memory_type.rs
@@ -0,0 +1,158 @@
+use {
+    super::{BlockFlavor, HeapsConfig},
+    crate::{allocator::*, usage::MemoryUsage, utilization::*},
+    gfx_hal::memory::Properties,
+};
+
+#[derive(Debug)]
+pub(super) struct MemoryType<B: gfx_hal::Backend> {
+    heap_index: usize,
+    properties: Properties,
+    dedicated: DedicatedAllocator,
+    linear: Option<LinearAllocator<B>>,
+    dynamic: Option<DynamicAllocator<B>>,
+    // chunk: Option<ChunkAllocator>,
+    used: u64,
+    effective: u64,
+}
+
+impl<B> MemoryType<B>
+where
+    B: gfx_hal::Backend,
+{
+    pub(super) fn new(
+        memory_type: gfx_hal::MemoryTypeId,
+        heap_index: usize,
+        properties: Properties,
+        config: HeapsConfig,
+        non_coherent_atom_size: u64,
+    ) -> Self {
+        MemoryType {
+            properties,
+            heap_index,
+            dedicated: DedicatedAllocator::new(memory_type, properties, non_coherent_atom_size),
+            linear: if properties.contains(Properties::CPU_VISIBLE) {
+                config.linear.map(|config| {
+                    LinearAllocator::new(memory_type, properties, config, non_coherent_atom_size)
+                })
+            } else {
+                None
+            },
+            dynamic: config.dynamic.map(|config| {
+                DynamicAllocator::new(memory_type, properties, config, non_coherent_atom_size)
+            }),
+            used: 0,
+            effective: 0,
+        }
+    }
+
+    pub(super) fn properties(&self) -> Properties {
+        self.properties
+    }
+
+    pub(super) fn heap_index(&self) -> usize {
+        self.heap_index
+    }
+
+    pub(super) fn alloc(
+        &mut self,
+        device: &B::Device,
+        usage: impl MemoryUsage,
+        size: u64,
+        align: u64,
+    ) -> Result<(BlockFlavor<B>, u64), gfx_hal::device::AllocationError> {
+        let (block, allocated) = self.alloc_impl(device, usage, size, align)?;
+        self.effective += block.size();
+        self.used += allocated;
+        Ok((block, allocated))
+    }
+
+    fn alloc_impl(
+        &mut self,
+        device: &B::Device,
+        usage: impl MemoryUsage,
+        size: u64,
+        align: u64,
+    ) -> Result<(BlockFlavor<B>, u64), gfx_hal::device::AllocationError> {
+        match (self.dynamic.as_mut(), self.linear.as_mut()) {
+            (Some(dynamic), Some(linear)) => {
+                if dynamic.max_allocation() >= size
+                    && usage.allocator_fitness(Kind::Dynamic)
+                        > usage.allocator_fitness(Kind::Linear)
+                {
+                    dynamic
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Dynamic(block), size))
+                } else if linear.max_allocation() >= size
+                    && usage.allocator_fitness(Kind::Linear) > 0
+                {
+                    linear
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Linear(block), size))
+                } else {
+                    self.dedicated
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Dedicated(block), size))
+                }
+            }
+            (Some(dynamic), None) => {
+                if dynamic.max_allocation() >= size && usage.allocator_fitness(Kind::Dynamic) > 0 {
+                    dynamic
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Dynamic(block), size))
+                } else {
+                    self.dedicated
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Dedicated(block), size))
+                }
+            }
+            (None, Some(linear)) => {
+                if linear.max_allocation() >= size && usage.allocator_fitness(Kind::Linear) > 0 {
+                    linear
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Linear(block), size))
+                } else {
+                    self.dedicated
+                        .alloc(device, size, align)
+                        .map(|(block, size)| (BlockFlavor::Dedicated(block), size))
+                }
+            }
+            (None, None) => self
+                .dedicated
+                .alloc(device, size, align)
+                .map(|(block, size)| (BlockFlavor::Dedicated(block), size)),
+        }
+    }
+
+    pub(super) fn free(&mut self, device: &B::Device, block: BlockFlavor<B>) -> u64 {
+        match block {
+            BlockFlavor::Dedicated(block) => self.dedicated.free(device, block),
+            BlockFlavor::Linear(block) => self.linear.as_mut().unwrap().free(device, block),
+            BlockFlavor::Dynamic(block) => self.dynamic.as_mut().unwrap().free(device, block),
+        }
+    }
+
+    pub(super) fn dispose(self, device: &B::Device) {
+        log::trace!("Dispose memory allocators");
+
+        if let Some(linear) = self.linear {
+            linear.dispose(device);
+            log::trace!("Linear allocator disposed");
+        }
+        if let Some(dynamic) = self.dynamic {
+            dynamic.dispose();
+            log::trace!("Dynamic allocator disposed");
+        }
+    }
+
+    pub(super) fn utilization(&self) -> MemoryTypeUtilization {
+        MemoryTypeUtilization {
+            utilization: MemoryUtilization {
+                used: self.used,
+                effective: self.effective,
+            },
+            properties: self.properties,
+            heap_index: self.heap_index,
+        }
+    }
+}
diff --git a/rendy-memory/src/heaps/mod.rs b/rendy-memory/src/heaps/mod.rs
new file mode 100644
index 0000000..0dd7983
--- /dev/null
+++ b/rendy-memory/src/heaps/mod.rs
@@ -0,0 +1,327 @@
+mod heap;
+mod memory_type;
+
+use {
+    self::{heap::MemoryHeap, memory_type::MemoryType},
+    crate::{allocator::*, block::Block, mapping::*, usage::MemoryUsage, util::*, utilization::*},
+    std::ops::Range,
+};
+
+/// Possible errors returned by `Heaps`.
+#[allow(missing_copy_implementations)]
+#[derive(Clone, Debug, PartialEq)]
+pub enum HeapsError {
+    /// Memory allocation failure.
+    AllocationError(gfx_hal::device::AllocationError),
+    /// No memory types among required for resource with requested properties was found.
+    NoSuitableMemory(u32, gfx_hal::memory::Properties),
+}
+
+impl std::fmt::Display for HeapsError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            HeapsError::AllocationError(e) => write!(f, "{:?}", e),
+            HeapsError::NoSuitableMemory(e, e2) => write!(
+                f,
+                "Memory type among ({}) with properties ({:?}) not found",
+                e, e2
+            ),
+        }
+    }
+}
+impl std::error::Error for HeapsError {}
+
+impl From<gfx_hal::device::AllocationError> for HeapsError {
+    fn from(error: gfx_hal::device::AllocationError) -> Self {
+        HeapsError::AllocationError(error)
+    }
+}
+
+impl From<gfx_hal::device::OutOfMemory> for HeapsError {
+    fn from(error: gfx_hal::device::OutOfMemory) -> Self {
+        HeapsError::AllocationError(error.into())
+    }
+}
+
+/// Config for `Heaps` allocator.
+#[derive(Clone, Copy, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct HeapsConfig {
+    /// Config for linear sub-allocator.
+    pub linear: Option<LinearConfig>,
+
+    /// Config for dynamic sub-allocator.
+    pub dynamic: Option<DynamicConfig>,
+}
+
+/// Heaps available on particular physical device.
+#[derive(Debug)]
+pub struct Heaps<B: gfx_hal::Backend> {
+    types: Vec<MemoryType<B>>,
+    heaps: Vec<MemoryHeap>,
+}
+
+impl<B> Heaps<B>
+where
+    B: gfx_hal::Backend,
+{
+    /// This must be called with `gfx_hal::memory::Properties` fetched from physical device.
+    pub unsafe fn new<P, H>(types: P, heaps: H, non_coherent_atom_size: u64) -> Self
+    where
+        P: IntoIterator<Item = (gfx_hal::memory::Properties, u32, HeapsConfig)>,
+        H: IntoIterator<Item = u64>,
+    {
+        let heaps = heaps.into_iter().map(MemoryHeap::new).collect::<Vec<_>>();
+        Heaps {
+            types: types
+                .into_iter()
+                .enumerate()
+                .map(|(index, (properties, heap_index, config))| {
+                    assert!(
+                        fits_u32(index),
+                        "Number of memory types must fit in u32 limit"
+                    );
+                    assert!(
+                        fits_usize(heap_index),
+                        "Number of memory types must fit in u32 limit"
+                    );
+                    let memory_type = gfx_hal::MemoryTypeId(index);
+                    let heap_index = heap_index as usize;
+                    assert!(heap_index < heaps.len());
+                    MemoryType::new(
+                        memory_type,
+                        heap_index,
+                        properties,
+                        config,
+                        non_coherent_atom_size,
+                    )
+                })
+                .collect(),
+            heaps,
+        }
+    }
+
+    /// Allocate memory block
+    /// from one of memory types specified by `mask`,
+    /// for intended `usage`,
+    /// with `size`
+    /// and `align` requirements.
+    pub fn allocate(
+        &mut self,
+        device: &B::Device,
+        mask: u32,
+        usage: impl MemoryUsage,
+        size: u64,
+        align: u64,
+    ) -> Result<MemoryBlock<B>, HeapsError> {
+        debug_assert!(fits_u32(self.types.len()));
+
+        let (memory_index, _, _) = {
+            let suitable_types = self
+                .types
+                .iter()
+                .enumerate()
+                .filter(|(index, _)| (mask & (1u32 << index)) != 0)
+                .filter_map(|(index, mt)| {
+                    if mt.properties().contains(usage.properties_required()) {
+                        let fitness = usage.memory_fitness(mt.properties());
+                        Some((index, mt, fitness))
+                    } else {
+                        None
+                    }
+                })
+                .collect::<smallvec::SmallVec<[_; 64]>>();
+
+            if suitable_types.is_empty() {
+                return Err(HeapsError::NoSuitableMemory(
+                    mask,
+                    usage.properties_required(),
+                ));
+            }
+
+            suitable_types
+                .into_iter()
+                .filter(|(_, mt, _)| self.heaps[mt.heap_index()].available() > size + align)
+                .max_by_key(|&(_, _, fitness)| fitness)
+                .ok_or_else(|| {
+                    log::error!("All suitable heaps are exhausted. {:#?}", self);
+                    gfx_hal::device::OutOfMemory::Device
+                })?
+        };
+
+        self.allocate_from(device, memory_index as u32, usage, size, align)
+    }
+
+    /// Allocate memory block
+    /// from `memory_index` specified,
+    /// for intended `usage`,
+    /// with `size`
+    /// and `align` requirements.
+    fn allocate_from(
+        &mut self,
+        device: &B::Device,
+        memory_index: u32,
+        usage: impl MemoryUsage,
+        size: u64,
+        align: u64,
+    ) -> Result<MemoryBlock<B>, HeapsError> {
+        log::trace!(
+            "Allocate memory block: type '{}', usage '{:#?}', size: '{}', align: '{}'",
+            memory_index,
+            usage,
+            size,
+            align
+        );
+        assert!(fits_usize(memory_index));
+
+        let memory_type = &mut self.types[memory_index as usize];
+        let memory_heap = &mut self.heaps[memory_type.heap_index()];
+
+        if memory_heap.available() < size {
+            return Err(gfx_hal::device::OutOfMemory::Device.into());
+        }
+
+        let (block, allocated) = memory_type.alloc(device, usage, size, align)?;
+        memory_heap.allocated(allocated, block.size());
+
+        Ok(MemoryBlock {
+            block,
+            memory_index,
+        })
+    }
+
+    /// Free memory block.
+    ///
+    /// Memory block must be allocated from this heap.
+    pub fn free(&mut self, device: &B::Device, block: MemoryBlock<B>) {
+        // trace!("Free block '{:#?}'", block);
+        let memory_index = block.memory_index;
+        debug_assert!(fits_usize(memory_index));
+        let size = block.size();
+
+        let memory_type = &mut self.types[memory_index as usize];
+        let memory_heap = &mut self.heaps[memory_type.heap_index()];
+        let freed = memory_type.free(device, block.block);
+        memory_heap.freed(freed, size);
+    }
+
+    /// Dispose of allocator.
+    /// Cleanup allocators before dropping.
+    /// Will panic if memory instances are left allocated.
+    pub fn dispose(self, device: &B::Device) {
+        for mt in self.types {
+            mt.dispose(device)
+        }
+    }
+
+    /// Get memory utilization.
+    pub fn utilization(&self) -> TotalMemoryUtilization {
+        TotalMemoryUtilization {
+            heaps: self.heaps.iter().map(MemoryHeap::utilization).collect(),
+            types: self.types.iter().map(MemoryType::utilization).collect(),
+        }
+    }
+}
+
+/// Memory block allocated from `Heaps`.
+#[derive(Debug)]
+pub struct MemoryBlock<B: gfx_hal::Backend> {
+    block: BlockFlavor<B>,
+    memory_index: u32,
+}
+
+impl<B> MemoryBlock<B>
+where
+    B: gfx_hal::Backend,
+{
+    /// Get memory type id.
+    pub fn memory_type(&self) -> u32 {
+        self.memory_index
+    }
+}
+
+#[derive(Debug)]
+enum BlockFlavor<B: gfx_hal::Backend> {
+    Dedicated(DedicatedBlock<B>),
+    Linear(LinearBlock<B>),
+    Dynamic(DynamicBlock<B>),
+    // Chunk(ChunkBlock<B>),
+}
+
+macro_rules! any_block {
+    ($self:ident. $block:ident => $expr:expr) => {{
+        use self::BlockFlavor::*;
+        match $self.$block {
+            Dedicated($block) => $expr,
+            Linear($block) => $expr,
+            Dynamic($block) => $expr,
+            // Chunk($block) => $expr,
+        }
+    }};
+    (& $self:ident. $block:ident => $expr:expr) => {{
+        use self::BlockFlavor::*;
+        match &$self.$block {
+            Dedicated($block) => $expr,
+            Linear($block) => $expr,
+            Dynamic($block) => $expr,
+            // Chunk($block) => $expr,
+        }
+    }};
+    (&mut $self:ident. $block:ident => $expr:expr) => {{
+        use self::BlockFlavor::*;
+        match &mut $self.$block {
+            Dedicated($block) => $expr,
+            Linear($block) => $expr,
+            Dynamic($block) => $expr,
+            // Chunk($block) => $expr,
+        }
+    }};
+}
+
+impl<B> BlockFlavor<B>
+where
+    B: gfx_hal::Backend,
+{
+    #[inline]
+    fn size(&self) -> u64 {
+        use self::BlockFlavor::*;
+        match self {
+            Dedicated(block) => block.size(),
+            Linear(block) => block.size(),
+            Dynamic(block) => block.size(),
+            // Chunk(block) => block.size(),
+        }
+    }
+}
+
+impl<B> Block<B> for MemoryBlock<B>
+where
+    B: gfx_hal::Backend,
+{
+    #[inline]
+    fn properties(&self) -> gfx_hal::memory::Properties {
+        any_block!(&self.block => block.properties())
+    }
+
+    #[inline]
+    fn memory(&self) -> &B::Memory {
+        any_block!(&self.block => block.memory())
+    }
+
+    #[inline]
+    fn range(&self) -> Range<u64> {
+        any_block!(&self.block => block.range())
+    }
+
+    fn map<'a>(
+        &'a mut self,
+        device: &B::Device,
+        range: Range<u64>,
+    ) -> Result<MappedRange<'a, B>, gfx_hal::device::MapError> {
+        any_block!(&mut self.block => block.map(device, range))
+    }
+
+    fn unmap(&mut self, device: &B::Device) {
+        any_block!(&mut self.block => block.unmap(device))
+    }
+}
diff --git a/rendy-memory/src/lib.rs b/rendy-memory/src/lib.rs
new file mode 100644
index 0000000..a0653ee
--- /dev/null
+++ b/rendy-memory/src/lib.rs
@@ -0,0 +1,31 @@
+//! GPU memory management
+//!
+
+#![warn(
+    missing_debug_implementations,
+    missing_copy_implementations,
+    missing_docs,
+    trivial_casts,
+    trivial_numeric_casts,
+    unused_extern_crates,
+    unused_import_braces,
+    unused_qualifications
+)]
+mod allocator;
+mod block;
+mod heaps;
+mod mapping;
+mod memory;
+mod usage;
+mod util;
+mod utilization;
+
+pub use crate::{
+    allocator::*,
+    block::Block,
+    heaps::{Heaps, HeapsConfig, HeapsError, MemoryBlock},
+    mapping::{write::Write, Coherent, MappedRange, MaybeCoherent, NonCoherent},
+    memory::Memory,
+    usage::*,
+    utilization::*,
+};
diff --git a/rendy-memory/src/mapping/mod.rs b/rendy-memory/src/mapping/mod.rs
new file mode 100644
index 0000000..63b2f34
--- /dev/null
+++ b/rendy-memory/src/mapping/mod.rs
@@ -0,0 +1,345 @@
+mod range;
+pub(crate) mod write;
+
+use {
+    crate::{memory::Memory, util::*},
+    gfx_hal::{device::Device as _, Backend},
+    std::{ops::Range, ptr::NonNull},
+};
+
+pub(crate) use self::range::*;
+use self::write::{Write, WriteCoherent, WriteFlush};
+
+/// Non-coherent marker.
+#[derive(Clone, Copy, Debug)]
+pub struct NonCoherent;
+
+/// Coherent marker.
+#[derive(Clone, Copy, Debug)]
+pub struct Coherent;
+
+/// Value that contains either coherent marker or non-coherent marker.
+#[derive(Clone, Copy, Debug)]
+pub struct MaybeCoherent(bool);
+
+/// Represents range of the memory mapped to the host.
+/// Provides methods for safer host access to the memory.
+#[derive(Debug)]
+pub struct MappedRange<'a, B: Backend, C = MaybeCoherent> {
+    /// Memory object that is mapped.
+    memory: &'a Memory<B>,
+
+    /// Pointer to range mapped memory.
+    ptr: NonNull<u8>,
+
+    /// Range of mapped memory.
+    mapping_range: Range<u64>,
+
+    /// Mapping range requested by caller.
+    /// Must be subrange of `mapping_range`.
+    requested_range: Range<u64>,
+
+    /// Coherency marker
+    coherent: C,
+}
+
+impl<'a, B> MappedRange<'a, B>
+where
+    B: Backend,
+{
+    // /// Map range of memory.
+    // /// `range` is in memory object space.
+    // ///
+    // /// # Safety
+    // ///
+    // /// * Only one range for the given memory object can be mapped.
+    // /// * Memory object must be not mapped.
+    // /// * Memory object must be created with device specified.
+    // pub unsafe fn new(
+    //     memory: &'a Memory<B>,
+    //     device: &B::Device,
+    //     range: Range<u64>,
+    // ) -> Result<Self, gfx_hal::device::MapError> {
+    //     assert!(
+    //         range.start < range.end,
+    //         "Memory mapping region must have valid size"
+    //     );
+    //     assert!(
+    //         fits_usize(range.end - range.start),
+    //         "Range length must fit in usize"
+    //     );
+    //     assert!(memory.host_visible());
+
+    //     let ptr = device.map_memory(memory.raw(), range.clone())?;
+    //     assert!(
+    //         (ptr as usize).wrapping_neg() >= (range.end - range.start) as usize,
+    //         "Resulting pointer value + range length must fit in usize. Pointer: {:p}, range {:?}",
+    //         ptr,
+    //         range,
+    //     );
+
+    //     Ok(Self::from_raw(memory, NonNull::new_unchecked(ptr), range))
+    // }
+
+    /// Construct mapped range from raw mapping
+    ///
+    /// # Safety
+    ///
+    /// `memory` `range` must be mapped to host memory region pointer by `ptr`.
+    /// `range` is in memory object space.
+    /// `ptr` points to the `range.start` offset from memory origin.
+    pub(crate) unsafe fn from_raw(
+        memory: &'a Memory<B>,
+        ptr: NonNull<u8>,
+        mapping_range: Range<u64>,
+        requested_range: Range<u64>,
+    ) -> Self {
+        debug_assert!(
+            mapping_range.start < mapping_range.end,
+            "Memory mapping region must have valid size"
+        );
+
+        debug_assert!(
+            requested_range.start < requested_range.end,
+            "Memory mapping region must have valid size"
+        );
+
+        if !memory.host_coherent() {
+            debug_assert_eq!(mapping_range.start % memory.non_coherent_atom_size(), 0, "Bounds of non-coherent memory mapping ranges must be multiple of `Limits::non_coherent_atom_size`");
+            debug_assert_eq!(mapping_range.end % memory.non_coherent_atom_size(), 0, "Bounds of non-coherent memory mapping ranges must be multiple of `Limits::non_coherent_atom_size`");
+            debug_assert!(
+                is_sub_range(mapping_range.clone(), requested_range.clone()),
+                "`requested_range` must be sub-range of `mapping_range`",
+            );
+        } else {
+            debug_assert_eq!(mapping_range, requested_range);
+        }
+
+        MappedRange {
+            ptr,
+            mapping_range,
+            requested_range,
+            memory,
+            coherent: MaybeCoherent(memory.host_coherent()),
+        }
+    }
+
+    /// Get pointer to beginning of memory region.
+    /// i.e. to `range().start` offset from memory origin.
+    pub fn ptr(&self) -> NonNull<u8> {
+        mapped_sub_range(
+            self.ptr,
+            self.mapping_range.clone(),
+            self.requested_range.clone(),
+        )
+        .unwrap()
+    }
+
+    /// Get mapped range.
+    pub fn range(&self) -> Range<u64> {
+        self.requested_range.clone()
+    }
+
+    /// Fetch readable slice of sub-range to be read.
+    /// Invalidating range if memory is not coherent.
+    /// `range.end - range.start` must be multiple of `size_of::()`.
+    /// `mapping offset + range.start` must be multiple of `align_of::()`.
+    ///
+    /// # Safety
+    ///
+    /// * Caller must ensure that device won't write to the memory region until the borrowing ends.
+    /// * `T` Must be plain-old-data type compatible with data in mapped region.
+    pub unsafe fn read<'b, T>(
+        &'b mut self,
+        device: &B::Device,
+        range: Range<u64>,
+    ) -> Result<&'b [T], gfx_hal::device::MapError>
+    where
+        'a: 'b,
+        T: Copy,
+    {
+        debug_assert!(
+            range.start < range.end,
+            "Memory mapping region must have valid size"
+        );
+        debug_assert!(
+            fits_usize(range.end - range.start),
+            "Range length must fit in usize"
+        );
+
+        let sub_range = relative_to_sub_range(self.requested_range.clone(), range)
+            .ok_or(gfx_hal::device::MapError::OutOfBounds)?;
+
+        let ptr =
+            mapped_sub_range(self.ptr, self.mapping_range.clone(), sub_range.clone()).unwrap();
+
+        let size = (sub_range.end - sub_range.start) as usize;
+
+        if !self.coherent.0 {
+            let aligned_sub_range = align_range(sub_range, self.memory.non_coherent_atom_size());
+            debug_assert!(is_sub_range(
+                self.mapping_range.clone(),
+                aligned_sub_range.clone()
+            ));
+            device.invalidate_mapped_memory_ranges(std::iter::once((
+                self.memory.raw(),
+                gfx_hal::memory::Segment {
+                    offset: aligned_sub_range.start,
+                    size: Some(aligned_sub_range.end - aligned_sub_range.start),
+                },
+            )))?;
+        }
+
+        let slice = mapped_slice::<T>(ptr, size);
+        Ok(slice)
+    }
+
+    /// Fetch writer to the sub-region.
+    /// This writer will flush data on drop if written at least once.
+    ///
+    /// # Safety
+    ///
+    /// * Caller must ensure that device won't write to or read from the memory region.
+    pub unsafe fn write<'b, T: 'b>(
+        &'b mut self,
+        device: &'b B::Device,
+        range: Range<u64>,
+    ) -> Result<impl Write<T> + 'b, gfx_hal::device::MapError>
+    where
+        'a: 'b,
+        T: Copy,
+    {
+        assert!(
+            range.start < range.end,
+            "Memory mapping region must have valid size"
+        );
+        assert!(
+            fits_usize(range.end - range.start),
+            "Range length must fit in usize"
+        );
+
+        let sub_range = relative_to_sub_range(self.requested_range.clone(), range)
+            .ok_or(gfx_hal::device::MapError::OutOfBounds)?;
+
+        let ptr =
+            mapped_sub_range(self.ptr, self.mapping_range.clone(), sub_range.clone()).unwrap();
+
+        let size = (sub_range.end - sub_range.start) as usize;
+
+        let slice = mapped_slice_mut::<T>(ptr, size);
+
+        let memory = &self.memory;
+        let flush = if !self.coherent.0 {
+            let aligned_sub_range = align_range(sub_range, self.memory.non_coherent_atom_size());
+            debug_assert!(is_sub_range(
+                self.mapping_range.clone(),
+                aligned_sub_range.clone()
+            ));
+            Some(move || {
+                device
+                    .flush_mapped_memory_ranges(std::iter::once((
+                        memory.raw(),
+                        gfx_hal::memory::Segment {
+                            offset: aligned_sub_range.start,
+                            size: Some(aligned_sub_range.end - aligned_sub_range.start),
+                        },
+                    )))
+                    .expect("Should flush successfully");
+            })
+        } else {
+            None
+        };
+
+        Ok(WriteFlush { slice, flush })
+    }
+
+    /// Convert into mapped range with statically known coherency.
+    pub fn coherent(self) -> Result<MappedRange<'a, B, Coherent>, MappedRange<'a, B, NonCoherent>> {
+        if self.coherent.0 {
+            Ok(MappedRange {
+                memory: self.memory,
+                ptr: self.ptr,
+                mapping_range: self.mapping_range,
+                requested_range: self.requested_range,
+                coherent: Coherent,
+            })
+        } else {
+            Err(MappedRange {
+                memory: self.memory,
+                ptr: self.ptr,
+                mapping_range: self.mapping_range,
+                requested_range: self.requested_range,
+                coherent: NonCoherent,
+            })
+        }
+    }
+}
+
+impl<'a, B> From<MappedRange<'a, B, Coherent>> for MappedRange<'a, B>
+where
+    B: Backend,
+{
+    fn from(range: MappedRange<'a, B, Coherent>) -> Self {
+        MappedRange {
+            memory: range.memory,
+            ptr: range.ptr,
+            mapping_range: range.mapping_range,
+            requested_range: range.requested_range,
+            coherent: MaybeCoherent(true),
+        }
+    }
+}
+
+impl<'a, B> From<MappedRange<'a, B, NonCoherent>> for MappedRange<'a, B>
+where
+    B: Backend,
+{
+    fn from(range: MappedRange<'a, B, NonCoherent>) -> Self {
+        MappedRange {
+            memory: range.memory,
+            ptr: range.ptr,
+            mapping_range: range.mapping_range,
+            requested_range: range.requested_range,
+            coherent: MaybeCoherent(false),
+        }
+    }
+}
+
+impl<'a, B> MappedRange<'a, B, Coherent>
+where
+    B: Backend,
+{
+    /// Fetch writer to the sub-region.
+    ///
+    /// # Safety
+    ///
+    /// * Caller must ensure that device won't write to or read from the memory region.
+    pub unsafe fn write<'b, U: 'b>(
+        &'b mut self,
+        range: Range<u64>,
+    ) -> Result<impl Write<U> + 'b, gfx_hal::device::MapError>
+    where
+        U: Copy,
+    {
+        assert!(
+            range.start < range.end,
+            "Memory mapping region must have valid size"
+        );
+        assert!(
+            fits_usize(range.end - range.start),
+            "Range length must fit in usize"
+        );
+
+        let sub_range = relative_to_sub_range(self.requested_range.clone(), range)
+            .ok_or(gfx_hal::device::MapError::OutOfBounds)?;
+
+        let ptr =
+            mapped_sub_range(self.ptr, self.mapping_range.clone(), sub_range.clone()).unwrap();
+
+        let size = (sub_range.end - sub_range.start) as usize;
+
+        let slice = mapped_slice_mut::<U>(ptr, size);
+
+        Ok(WriteCoherent { slice })
+    }
+}
diff --git a/rendy-memory/src/mapping/range.rs b/rendy-memory/src/mapping/range.rs
new file mode 100644
index 0000000..f4c49be
--- /dev/null
+++ b/rendy-memory/src/mapping/range.rs
@@ -0,0 +1,85 @@
+use {
+    crate::util::fits_usize,
+    std::{
+        mem::{align_of, size_of},
+        ops::Range,
+        ptr::NonNull,
+        slice::{from_raw_parts, from_raw_parts_mut},
+    },
+};
+
+/// Get sub-range of memory mapping.
+/// `range` and `fitting` are in memory object space.
+/// `ptr` points to the `range.start` offset from memory origin.
+/// returns pointer to `fitting.start` offset from memory origin
+/// if `fitting` is contained in `range`.
+pub(crate) fn mapped_sub_range(
+    ptr: NonNull<u8>,
+    range: Range<u64>,
+    fitting: Range<u64>,
+) -> Option<NonNull<u8>> {
+    assert!(
+        range.start < range.end,
+        "Memory mapping region must have valid size"
+    );
+    assert!(
+        fitting.start < fitting.end,
+        "Memory mapping region must have valid size"
+    );
+    assert!(fits_usize(range.end - range.start));
+    assert!(usize::max_value() - (range.end - range.start) as usize >= ptr.as_ptr() as usize);
+
+    if fitting.start < range.start || fitting.end > range.end {
+        None
+    } else {
+        Some(unsafe {
+            // for x > 0 and y >= 0: x + y > 0. No overflow due to checks above.
+            NonNull::new_unchecked(
+                (ptr.as_ptr() as usize + (fitting.start - range.start) as usize) as *mut u8,
+            )
+        })
+    }
+}
+
+/// # Safety
+///
+/// User must ensure that:
+/// * this function won't create aliasing slices.
+/// * returned slice doesn't outlive mapping.
+/// * `T` Must be plain-old-data type compatible with data in mapped region.
+pub(crate) unsafe fn mapped_slice_mut<'a, T>(ptr: NonNull<u8>, size: usize) -> &'a mut [T] {
+    assert_eq!(
+        size % size_of::<T>(),
+        0,
+        "Range length must be multiple of element size"
+    );
+    let offset = ptr.as_ptr() as usize;
+    assert_eq!(
+        offset % align_of::<T>(),
+        0,
+        "Range offset must be multiple of element alignment"
+    );
+    assert!(usize::max_value() - size >= ptr.as_ptr() as usize);
+    from_raw_parts_mut(ptr.as_ptr() as *mut T, size)
+}
+
+/// # Safety
+///
+/// User must ensure that:
+/// * returned slice doesn't outlive mapping.
+/// * `T` Must be plain-old-data type compatible with data in mapped region.
+pub(crate) unsafe fn mapped_slice<'a, T>(ptr: NonNull<u8>, size: usize) -> &'a [T] {
+    assert_eq!(
+        size % size_of::<T>(),
+        0,
+        "Range length must be multiple of element size"
+    );
+    let offset = ptr.as_ptr() as usize;
+    assert_eq!(
+        offset % align_of::<T>(),
+        0,
+        "Range offset must be multiple of element alignment"
+    );
+    assert!(usize::max_value() - size >= ptr.as_ptr() as usize);
+    from_raw_parts(ptr.as_ptr() as *const T, size)
+}
diff --git a/rendy-memory/src/mapping/write.rs b/rendy-memory/src/mapping/write.rs
new file mode 100644
index 0000000..d067a61
--- /dev/null
+++ b/rendy-memory/src/mapping/write.rs
@@ -0,0 +1,73 @@
+use std::ptr::copy_nonoverlapping;
+
+/// Trait for memory region suitable for host writes.
+pub trait Write<T: Copy> {
+    /// Get mutable slice of `T` bound to mapped range.
+    ///
+    /// # Safety
+    ///
+    /// * Returned slice should not be read.
+    unsafe fn slice(&mut self) -> &mut [T];
+
+    /// Write data into mapped memory sub-region.
+    ///
+    /// # Panic
+    ///
+    /// Panics if `data.len()` is greater than this sub-region len.
+    fn write(&mut self, data: &[T]) {
+        unsafe {
+            let slice = self.slice();
+            assert!(data.len() <= slice.len());
+            copy_nonoverlapping(data.as_ptr(), slice.as_mut_ptr(), data.len());
+        }
+    }
+}
+
+#[derive(Debug)]
+pub(super) struct WriteFlush<'a, T, F: FnOnce() + 'a> {
+    pub(super) slice: &'a mut [T],
+    pub(super) flush: Option<F>,
+}
+
+impl<'a, T, F> Drop for WriteFlush<'a, T, F>
+where
+    T: 'a,
+    F: FnOnce() + 'a,
+{
+    fn drop(&mut self) {
+        if let Some(f) = self.flush.take() {
+            f();
+        }
+    }
+}
+
+impl<'a, T, F> Write<T> for WriteFlush<'a, T, F>
+where
+    T: Copy + 'a,
+    F: FnOnce() + 'a,
+{
+    /// # Safety
+    ///
+    /// [See doc comment for trait method](trait.Write#method.slice)
+    unsafe fn slice(&mut self) -> &mut [T] {
+        self.slice
+    }
+}
+
+#[warn(dead_code)]
+#[derive(Debug)]
+pub(super) struct WriteCoherent<'a, T> {
+    pub(super) slice: &'a mut [T],
+}
+
+impl<'a, T> Write<T> for WriteCoherent<'a, T>
+where
+    T: Copy + 'a,
+{
+    /// # Safety
+    ///
+    /// [See doc comment for trait method](trait.Write#method.slice)
+    unsafe fn slice(&mut self) -> &mut [T] {
+        self.slice
+    }
+}
diff --git a/rendy-memory/src/memory.rs b/rendy-memory/src/memory.rs
new file mode 100644
index 0000000..a529efe
--- /dev/null
+++ b/rendy-memory/src/memory.rs
@@ -0,0 +1,98 @@
+// use std::fmt;
+
+/// Memory object wrapper.
+/// Contains size and properties of the memory.
+#[derive(Debug)]
+pub struct Memory<B: gfx_hal::Backend> {
+    raw: B::Memory,
+    size: u64,
+    properties: gfx_hal::memory::Properties,
+    non_coherent_atom_size: u64,
+    relevant: relevant::Relevant,
+}
+
+impl<B> Memory<B>
+where
+    B: gfx_hal::Backend,
+{
+    /// Get memory properties.
+    pub fn properties(&self) -> gfx_hal::memory::Properties {
+        self.properties
+    }
+
+    /// Get memory size.
+    pub fn size(&self) -> u64 {
+        self.size
+    }
+
+    /// Get raw memory.
+    pub fn raw(&self) -> &B::Memory {
+        &self.raw
+    }
+
+    /// Get raw memory mutably.
+    pub fn raw_mut(&mut self) -> &mut B::Memory {
+        &mut self.raw
+    }
+
+    /// Unwrap raw memory.
+    pub fn into_raw(self) -> B::Memory {
+        self.relevant.dispose();
+        self.raw
+    }
+
+    pub(crate) fn non_coherent_atom_size(&self) -> u64 {
+        debug_assert!(
+            self.host_visible() && !self.host_coherent(),
+            "Irrelevent and shouldn't be called",
+        );
+        self.non_coherent_atom_size
+    }
+
+    /// Create memory from raw object.
+    ///
+    /// # Safety
+    ///
+    /// TODO:
+    pub unsafe fn from_raw(
+        raw: B::Memory,
+        size: u64,
+        properties: gfx_hal::memory::Properties,
+        non_coherent_atom_size: u64,
+    ) -> Self {
+        Memory {
+            properties,
+            raw,
+            size,
+            non_coherent_atom_size,
+            relevant: relevant::Relevant,
+        }
+    }
+
+    /// Check if this memory is host-visible and can be mapped.
+    /// `memory.host_visible()` is equivalent to `memory.properties().contains(Properties::CPU_VISIBLE)`
+    pub fn host_visible(&self) -> bool {
+        self.properties
+            .contains(gfx_hal::memory::Properties::CPU_VISIBLE)
+    }
+
+    /// Check if this memory is host-coherent and doesn't require invalidating or flushing.
+    /// `memory.host_coherent()` is equivalent to `memory.properties().contains(Properties::COHERENT)`
+    pub fn host_coherent(&self) -> bool {
+        self.properties
+            .contains(gfx_hal::memory::Properties::COHERENT)
+    }
+}
+
+// pub(crate) fn memory_ptr_fmt(
+//     memory: &*const Memory,
+//     fmt: &mut fmt::Formatter<'_>,
+// ) -> Result<(), fmt::Error> {
+//     unsafe {
+//         if fmt.alternate() {
+//             write!(fmt, "*const {:#?}", **memory)
+//         } else {
+//             write!(fmt, "*const {:?}", **memory)
+//         }
+//     }
+// }
diff --git a/rendy-memory/src/usage.rs b/rendy-memory/src/usage.rs
new file mode 100644
index 0000000..a9a4012
--- /dev/null
+++ b/rendy-memory/src/usage.rs
@@ -0,0 +1,210 @@
+//! Defines usage types for memory bocks.
+//! See `Usage` and implementations for details.
+
+use crate::allocator::Kind;
+
+/// Memory usage trait.
+pub trait MemoryUsage: std::fmt::Debug {
+    /// Get set of properties required for the usage.
+    fn properties_required(&self) -> gfx_hal::memory::Properties;
+
+    /// Get comparable fitness value for memory properties.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic if properties set doesn't contain required properties.
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32;
+
+    /// Get comparable fitness value for memory allocator.
+    fn allocator_fitness(&self, kind: Kind) -> u32;
+}
+
+impl<T> MemoryUsage for T
+where
+    T: std::ops::Deref + std::fmt::Debug,
+    T::Target: MemoryUsage,
+{
+    fn properties_required(&self) -> gfx_hal::memory::Properties {
+        (&**self).properties_required()
+    }
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32 {
+        (&**self).memory_fitness(properties)
+    }
+    fn allocator_fitness(&self, kind: Kind) -> u32 {
+        (&**self).allocator_fitness(kind)
+    }
+}
+
+/// Full speed GPU access.
+/// Optimal for render targets and persistent resources.
+/// Avoid memory with host access.
+#[derive(Clone, Copy, Debug)]
+pub struct Data;
+
+impl MemoryUsage for Data {
+    fn properties_required(&self) -> gfx_hal::memory::Properties {
+        gfx_hal::memory::Properties::DEVICE_LOCAL
+    }
+
+    #[inline]
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32 {
+        assert!(properties.contains(gfx_hal::memory::Properties::DEVICE_LOCAL));
+        0 | ((!properties.contains(gfx_hal::memory::Properties::CPU_VISIBLE)) as u32) << 3
+            | ((!properties.contains(gfx_hal::memory::Properties::LAZILY_ALLOCATED)) as u32) << 2
+            | ((!properties.contains(gfx_hal::memory::Properties::CPU_CACHED)) as u32) << 1
+            | ((!properties.contains(gfx_hal::memory::Properties::COHERENT)) as u32) << 0
+    }
+
+    fn allocator_fitness(&self, kind: Kind) -> u32 {
+        match kind {
+            Kind::Dedicated => 1,
+            Kind::Dynamic => 2,
+            Kind::Linear => 0,
+        }
+    }
+}
+
+/// CPU to GPU data flow with update commands.
+/// Used for dynamic buffer data, typically constant buffers.
+/// Host access is guaranteed.
+/// Prefers memory with fast GPU access.
+#[derive(Clone, Copy, Debug)]
+pub struct Dynamic;
+
+impl MemoryUsage for Dynamic {
+    fn properties_required(&self) -> gfx_hal::memory::Properties {
+        gfx_hal::memory::Properties::CPU_VISIBLE
+    }
+
+    #[inline]
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32 {
+        assert!(properties.contains(gfx_hal::memory::Properties::CPU_VISIBLE));
+        assert!(!properties.contains(gfx_hal::memory::Properties::LAZILY_ALLOCATED));
+
+        0 | (properties.contains(gfx_hal::memory::Properties::DEVICE_LOCAL) as u32) << 2
+            | (properties.contains(gfx_hal::memory::Properties::COHERENT) as u32) << 1
+            | ((!properties.contains(gfx_hal::memory::Properties::CPU_CACHED)) as u32) << 0
+    }
+
+    fn allocator_fitness(&self, kind: Kind) -> u32 {
+        match kind {
+            Kind::Dedicated => 1,
+            Kind::Dynamic => 2,
+            Kind::Linear => 0,
+        }
+    }
+}
+
+/// CPU to GPU data flow with mapping.
+/// Used for staging data before copying to the `Data` memory.
+/// Host access is guaranteed.
+#[derive(Clone, Copy, Debug)]
+pub struct Upload;
+
+impl MemoryUsage for Upload {
+    fn properties_required(&self) -> gfx_hal::memory::Properties {
+        gfx_hal::memory::Properties::CPU_VISIBLE
+    }
+
+    #[inline]
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32 {
+        assert!(properties.contains(gfx_hal::memory::Properties::CPU_VISIBLE));
+        assert!(!properties.contains(gfx_hal::memory::Properties::LAZILY_ALLOCATED));
+
+        0 | ((!properties.contains(gfx_hal::memory::Properties::DEVICE_LOCAL)) as u32) << 2
+            | (properties.contains(gfx_hal::memory::Properties::COHERENT) as u32) << 1
+            | ((!properties.contains(gfx_hal::memory::Properties::CPU_CACHED)) as u32) << 0
+    }
+
+    fn allocator_fitness(&self, kind: Kind) -> u32 {
+        match kind {
+            Kind::Dedicated => 0,
+            Kind::Dynamic => 1,
+            Kind::Linear => 2,
+        }
+    }
+}
+
+/// GPU to CPU data flow with mapping.
+/// Used for copying data from `Data` memory to be read by the host.
+/// Host access is guaranteed.
+#[derive(Clone, Copy, Debug)]
+pub struct Download;
+
+impl MemoryUsage for Download {
+    fn properties_required(&self) -> gfx_hal::memory::Properties {
+        gfx_hal::memory::Properties::CPU_VISIBLE
+    }
+
+    #[inline]
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32 {
+        assert!(properties.contains(gfx_hal::memory::Properties::CPU_VISIBLE));
+        assert!(!properties.contains(gfx_hal::memory::Properties::LAZILY_ALLOCATED));
+
+        0 | ((!properties.contains(gfx_hal::memory::Properties::DEVICE_LOCAL)) as u32) << 2
+            | (properties.contains(gfx_hal::memory::Properties::CPU_CACHED) as u32) << 1
+            | (properties.contains(gfx_hal::memory::Properties::COHERENT) as u32) << 0
+    }
+
+    fn allocator_fitness(&self, kind: Kind) -> u32 {
+        match kind {
+            Kind::Dedicated => 0,
+            Kind::Dynamic => 1,
+            Kind::Linear => 2,
+        }
+    }
+}
+
+/// Well-known memory usage types.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum MemoryUsageValue {
+    /// See [`Data`]
+    ///
+    /// [`Data`]: struct.Data.html
+    Data,
+
+    /// See [`Dynamic`]
+    ///
+    /// [`Dynamic`]: struct.Dynamic.html
+    Dynamic,
+
+    /// See [`Upload`]
+    ///
+    /// [`Upload`]: struct.Upload.html
+    Upload,
+
+    /// See [`Download`]
+    ///
+    /// [`Download`]: struct.Download.html
+    Download,
+}
+
+/// Memory usage trait.
+impl MemoryUsage for MemoryUsageValue {
+    fn properties_required(&self) -> gfx_hal::memory::Properties {
+        match self {
+            MemoryUsageValue::Data => Data.properties_required(),
+            MemoryUsageValue::Dynamic => Dynamic.properties_required(),
+            MemoryUsageValue::Upload => Upload.properties_required(),
+            MemoryUsageValue::Download => Download.properties_required(),
+        }
+    }
+
+    fn memory_fitness(&self, properties: gfx_hal::memory::Properties) -> u32 {
+        match self {
+            MemoryUsageValue::Data => Data.memory_fitness(properties),
+            MemoryUsageValue::Dynamic => Dynamic.memory_fitness(properties),
+            MemoryUsageValue::Upload => Upload.memory_fitness(properties),
+            MemoryUsageValue::Download => Download.memory_fitness(properties),
+        }
+    }
+
+    fn allocator_fitness(&self, kind: Kind) -> u32 {
+        match self {
+            MemoryUsageValue::Data => Data.allocator_fitness(kind),
+            MemoryUsageValue::Dynamic => Dynamic.allocator_fitness(kind),
+            MemoryUsageValue::Upload => Upload.allocator_fitness(kind),
+            MemoryUsageValue::Download => Download.allocator_fitness(kind),
+        }
+    }
+}
diff --git a/rendy-memory/src/util.rs b/rendy-memory/src/util.rs
new file mode 100644
index 0000000..07b9b7c
--- /dev/null
+++ b/rendy-memory/src/util.rs
@@ -0,0 +1,157 @@
+pub(crate) fn aligned(value: u64, align: u64) -> u64 {
+    debug_assert_ne!(align, 0);
+    debug_assert_eq!(align.count_ones(), 1);
+    if value == 0 {
+        0
+    } else {
+        1u64 + ((value - 1u64) | (align - 1u64))
+    }
+}
+
+pub(crate) trait IntegerFitting {
+    fn fits_usize(self) -> bool;
+    fn fits_isize(self) -> bool;
+
+    fn usize_fits(value: usize) -> bool;
+    fn isize_fits(value: isize) -> bool;
+}
+
+#[cfg(any(target_pointer_width = "16", target_pointer_width = "32"))]
+impl IntegerFitting for u64 {
+    fn fits_usize(self) -> bool {
+        self <= usize::max_value() as u64
+    }
+    fn fits_isize(self) -> bool {
+        self <= isize::max_value() as u64
+    }
+    fn usize_fits(_value: usize) -> bool {
+        true
+    }
+    fn isize_fits(value: isize) -> bool {
+        value >= 0
+    }
+}
+
+#[cfg(target_pointer_width = "64")]
+impl IntegerFitting for u64 {
+    fn fits_usize(self) -> bool {
+        true
+    }
+    fn fits_isize(self) -> bool {
+        self <= isize::max_value() as u64
+    }
+    fn usize_fits(_value: usize) -> bool {
+        true
+    }
+    fn isize_fits(value: isize) -> bool {
+        value >= 0
+    }
+}
+
+#[cfg(not(any(
+    target_pointer_width = "16",
+    target_pointer_width = "32",
+    target_pointer_width = "64"
+)))]
+impl IntegerFitting for u64 {
+    fn fits_usize(self) -> bool {
+        true
+    }
+    fn fits_isize(self) -> bool {
+        true
+    }
+    fn usize_fits(value: usize) -> bool {
+        value <= u64::max_value() as usize
+    }
+    fn isize_fits(value: isize) -> bool {
+        value >= 0 && value <= u64::max_value() as isize
+    }
+}
+
+#[cfg(target_pointer_width = "16")]
+impl IntegerFitting for u32 {
+    fn fits_usize(self) -> bool {
+        self <= usize::max_value() as u32
+    }
+    fn fits_isize(self) -> bool {
+        self <= isize::max_value() as u32
+    }
+    fn usize_fits(_value: usize) -> bool {
+        true
+    }
+    fn isize_fits(value: isize) -> bool {
+        value >= 0
+    }
+}
+
+#[cfg(target_pointer_width = "32")]
+impl IntegerFitting for u32 {
+    fn fits_usize(self) -> bool {
+        true
+    }
+    fn fits_isize(self) -> bool {
+        self <= isize::max_value() as u32
+    }
+    fn usize_fits(_value: usize) -> bool {
+        true
+    }
+    fn isize_fits(value: isize) -> bool {
+        value >= 0
+    }
+}
+
+#[cfg(not(any(target_pointer_width = "16", target_pointer_width = "32")))]
+impl IntegerFitting for u32 {
+    fn fits_usize(self) -> bool {
+        true
+    }
+    fn fits_isize(self) -> bool {
+        true
+    }
+    fn usize_fits(value: usize) -> bool {
+        value <= u32::max_value() as usize
+    }
+    fn isize_fits(value: isize) -> bool {
+        value >= 0 && value <= u32::max_value() as isize
+    }
+}
+
+pub(crate) fn fits_usize<T: IntegerFitting>(value: T) -> bool {
+    value.fits_usize()
+}
+
+pub(crate) fn fits_u32(value: usize) -> bool {
+    u32::usize_fits(value)
+}
+
+pub(crate) fn align_range(range: std::ops::Range<u64>, align: u64) -> std::ops::Range<u64> {
+    let start = range.start - range.start % align;
+    let end = ((range.end - 1) / align + 1) * align;
+    start..end
+}
+
+pub(crate) fn align_size(size: u64, align: u64) -> u64 {
+    ((size - 1) / align + 1) * align
+}
+
+pub(crate) fn is_non_coherent_visible(properties: gfx_hal::memory::Properties) -> bool {
+    properties & (gfx_hal::memory::Properties::CPU_VISIBLE | gfx_hal::memory::Properties::COHERENT)
+        == gfx_hal::memory::Properties::CPU_VISIBLE
+}
+
+pub(crate) fn relative_to_sub_range(
+    range: std::ops::Range<u64>,
+    relative: std::ops::Range<u64>,
+) -> Option<std::ops::Range<u64>> {
+    let start = relative.start + range.start;
+    let end = relative.end + range.start;
+    if end <= range.end {
+        Some(start..end)
+    } else {
+        None
+    }
+}
+
+pub(crate) fn is_sub_range(range: std::ops::Range<u64>, sub: std::ops::Range<u64>) -> bool {
+    sub.start >= range.start && sub.end <= range.end
+}
diff --git a/rendy-memory/src/utilization.rs b/rendy-memory/src/utilization.rs
new file mode 100644
index 0000000..723c429
--- /dev/null
+++ b/rendy-memory/src/utilization.rs
@@ -0,0 +1,137 @@
+use {
+    colorful::{core::color_string::CString, Color, Colorful as _},
+    gfx_hal::memory::Properties,
+};
+
+/// Memory utilization stats.
+#[derive(Clone, Copy, Debug)]
+pub struct MemoryUtilization {
+    /// Total number of bytes allocated.
+    pub used: u64,
+    /// Effective number bytes allocated.
+    pub effective: u64,
+}
+
+/// Memory utilization of one heap.
+#[derive(Clone, Copy, Debug)]
+pub struct MemoryHeapUtilization {
+    /// Utilization.
+    pub utilization: MemoryUtilization,
+
+    /// Memory heap size.
+    pub size: u64,
+}
+
+/// Memory utilization of one type.
+#[derive(Clone, Copy, Debug)]
+pub struct MemoryTypeUtilization {
+    /// Utilization.
+    pub utilization: MemoryUtilization,
+
+    /// Memory type info.
+    pub properties: Properties,
+
+    /// Index of heap this memory type uses.
+    pub heap_index: usize,
+}
+
+/// Total memory utilization.
+#[derive(Clone, Debug)]
+pub struct TotalMemoryUtilization {
+    /// Utilization by types.
+    pub types: Vec<MemoryTypeUtilization>,
+
+    /// Utilization by heaps.
+    pub heaps: Vec<MemoryHeapUtilization>,
+}
+
+impl std::fmt::Display for TotalMemoryUtilization {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        const MB: u64 = 1024 * 1024;
+
+        writeln!(fmt, "!!! Memory utilization !!!")?;
+        for (index, heap) in self.heaps.iter().enumerate() {
+            let size = heap.size;
+            let MemoryUtilization { used, effective } = heap.utilization;
+            let usage_basis_points = used * 10000 / size;
+            let fill = if usage_basis_points > 10000 {
+                // Shouldn't happen, but just in case.
+                50
+            } else {
+                (usage_basis_points / 200) as usize
+            };
+            let effective_basis_points = if used > 0 {
+                effective * 10000 / used
+            } else {
+                10000
+            };
+
+            let line = ("|".repeat(fill) + &(" ".repeat(50 - fill)))
+                .gradient_with_color(Color::Green, Color::Red);
+            writeln!(
+                fmt,
+                "Heap {}:\n{:6} / {:<6} or{} {{ effective:{} }} [{}]",
+                format!("{}", index).magenta(),
+                format!("{}MB", used / MB),
+                format!("{}MB", size / MB),
+                format_basis_points(usage_basis_points),
+                format_basis_points_inverted(effective_basis_points),
+                line
+            )?;
+
+            for ty in self.types.iter().filter(|ty| ty.heap_index == index) {
+                let properties = ty.properties;
+                let MemoryUtilization { used, effective } = ty.utilization;
+                let usage_basis_points = used * 10000 / size;
+                let effective_basis_points = if used > 0 {
+                    effective * 10000 / used
+                } else {
+                    0
+                };
+
+                writeln!(
+                    fmt,
+                    "         {:>6} or{} {{ effective:{} }} | {:?}",
+                    format!("{}MB", used / MB),
+                    format_basis_points(usage_basis_points),
+                    format_basis_points_inverted(effective_basis_points),
+                    properties,
+                )?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+fn format_basis_points(basis_points: u64) -> CString {
+    debug_assert!(basis_points <= 10000);
+    let s = format!("{:>3}.{:02}%", basis_points / 100, basis_points % 100);
+    if basis_points > 7500 {
+        s.red()
+    } else if basis_points > 5000 {
+        s.yellow()
+    } else if basis_points > 2500 {
+        s.green()
+    } else if basis_points > 100 {
+        s.blue()
+    } else {
+        s.white()
+    }
+}
+
+fn format_basis_points_inverted(basis_points: u64) -> CString {
+    debug_assert!(basis_points <= 10000);
+    let s = format!("{:>3}.{:02}%", basis_points / 100, basis_points % 100);
+    if basis_points > 9900 {
+        s.white()
+    } else if basis_points > 7500 {
+        s.blue()
+    } else if basis_points > 5000 {
+        s.green()
+    } else if basis_points > 2500 {
+        s.yellow()
+    } else {
+        s.red()
+    }
+}