Resource that uses system memory resource to allocate memory with a headroom. More...

#include <sam_headroom_memory_resource.hpp>

Inheritance diagram for rmm::mr::sam_headroom_memory_resource:

Collaboration diagram for rmm::mr::sam_headroom_memory_resource:

Public Member Functions
	sam_headroom_memory_resource (std::size_t headroom)
	Construct a headroom memory resource. More...

	sam_headroom_memory_resource (sam_headroom_memory_resource const &)=default
	Default copy constructor.

	sam_headroom_memory_resource (sam_headroom_memory_resource &&)=default
	Default move constructor.

sam_headroom_memory_resource &	operator= (sam_headroom_memory_resource const &)=default
	Default copy assignment operator. More...

sam_headroom_memory_resource &	operator= (sam_headroom_memory_resource &&)=default
	Default move assignment operator. More...

Friends
void	get_property (sam_headroom_memory_resource const &, cuda::mr::device_accessible) noexcept
	Enables the `cuda::mr::device_accessible` property.

void	get_property (sam_headroom_memory_resource const &, cuda::mr::host_accessible) noexcept
	Enables the `cuda::mr::host_accessible` property.

Detailed Description

Resource that uses system memory resource to allocate memory with a headroom.

System allocated memory (SAM) can be migrated to the GPU, but is never migrated back the host. If GPU memory is over-subscribed, this can cause other CUDA calls to fail with out-of-memory errors. To work around this problem, when using a system memory resource, we reserve some GPU memory as headroom for other CUDA calls, and only conditionally set its preferred location to the GPU if the allocation would not eat into the headroom.

Since doing this check on every allocation can be expensive, the caller may choose to use other allocators (e.g. binning_memory_resource) for small allocations, and use this allocator for large allocations only.

Constructor & Destructor Documentation

◆ sam_headroom_memory_resource()

rmm::mr::sam_headroom_memory_resource::sam_headroom_memory_resource ( std::size_t headroom )

explicit

Construct a headroom memory resource.

Parameters

headroom Size of the reserved GPU memory as headroom

Member Function Documentation

◆ operator=() [1/2]

sam_headroom_memory_resource& rmm::mr::sam_headroom_memory_resource::operator= ( sam_headroom_memory_resource && )

default

Default move assignment operator.

Returns: sam_headroom_memory_resource& Reference to the assigned object

◆ operator=() [2/2]

sam_headroom_memory_resource& rmm::mr::sam_headroom_memory_resource::operator= ( sam_headroom_memory_resource const & )

default

Default copy assignment operator.

Returns: sam_headroom_memory_resource& Reference to the assigned object

The documentation for this class was generated from the following file:

sam_headroom_memory_resource.hpp