kotovalexarian-likes-github/ruby--ruby
1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
Code Releases Activity

Add struct fiber_pool {int free_stacks;} to control usage of madvise.

Browse source 
`madvise(free)` and similar operations are good because they avoid swap
usage by clearing the dirty bit on memory pages which are mapped but no
longer needed. However, there is some performance penalty if there is no
memory pressure. Therefore, we do it by default, but it can be avoided.
This commit is contained in:
Samuel Williams 2019-07-16 16:00:35 +12:00
parent 4d60a5820a
commit 385ea910fc
No known key found for this signature in database
GPG key ID: A0765423A44728FB
1 changed files with 10 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
cont.c
View file

@ -157,6 +157,9 @@ struct fiber_pool {
// The initial number of stacks to allocate.
size_t initial_count;
// Whether to madvise(free) the stack or not:
int free_stacks;
// The number of stacks that have been used in this pool.
size_t used;
@ -479,6 +482,7 @@ fiber_pool_initialize(struct fiber_pool * fiber_pool, size_t size, size_t count,
fiber_pool->size = ((size / RB_PAGE_SIZE) + 1) * RB_PAGE_SIZE;
fiber_pool->count = 0;
fiber_pool->initial_count = count;
fiber_pool->free_stacks = 1;
fiber_pool->used = 0;
fiber_pool->vm_stack_size = vm_stack_size;
@ -612,7 +616,12 @@ fiber_pool_stack_release(struct fiber_pool_stack * stack) {
// Release address space and/or dirty memory:
if (stack->allocation->used == 0) {
fiber_pool_allocation_free(stack->allocation);
} else {
} else if (stack->pool->free_stacks) {
fiber_pool_stack_free(stack);
}
#else
// This is entirely optional, but clears the dirty flag from the stack memory, so it won't get swapped to disk when there is memory pressure:
if (stack->pool->free_stacks) {
fiber_pool_stack_free(stack);
}
#endif