seastar::memory Namespace Reference

Detailed Description

Low-level memory management support

The memory namespace provides functions and classes for interfacing with the seastar memory allocator.

The seastar memory allocator splits system memory into a pool per logical core (lcore). Memory allocated one an lcore should be freed on the same lcore; failing to do so carries a severe performance penalty. It is possible to share memory with another core, but this should be limited to avoid cache coherency traffic.

Classes
class	alloc_failure_injector
struct	disable_failure_guard
struct	memory_layout
class	scoped_large_allocation_warning_disable
	Disable large allocation warnings for a scope. More...
class	scoped_large_allocation_warning_threshold
	Set a different large allocation warning threshold for a scope. More...
class	statistics
	Memory allocation statistics. More...

Functions
statistics	stats ()
	Capture a snapshot of memory allocation statistics for this lcore.
memory::memory_layout	get_memory_layout ()
size_t	min_free_memory ()
void	set_min_free_pages (size_t pages)
	Sets the value of free memory low water mark in memory::page_size units.
void	set_large_allocation_warning_threshold (size_t threshold)
size_t	get_large_allocation_warning_threshold ()
	Gets the current large allocation warning threshold.
void	disable_large_allocation_warning ()
	Disable large allocation warnings.
alloc_failure_injector &	local_failure_injector ()
void	on_alloc_point ()

Variables
thread_local alloc_failure_injector	the_alloc_failure_injector

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Class Documentation

seastar::memory::memory_layout

struct seastar::memory::memory_layout

Class Members
uintptr_t	end
uintptr_t	start

Function Documentation

min_free_memory()

size_t seastar::memory::min_free_memory

(

)

Returns the value of free memory low water mark in bytes. When free memory is below this value, reclaimers are invoked until it goes above again.

set_large_allocation_warning_threshold()

void seastar::memory::set_large_allocation_warning_threshold

(

size_t

threshold

)

Enable the large allocation warning threshold.

Warn when allocation above a given threshold are performed.

Parameters

threshold

size (in bytes) above which an allocation will be logged