project-base/server-skynet-source-3rd-jemalloc
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Allocate tcache stack from base allocator

Browse Source 
When using metadata_thp, allocate tcache bin stacks from base0, which means they
will be placed on huge pages along with other metadata, instead of mixed with
other regular allocations.

In order to do so, modified the base allocator to support limited reuse: freed
tcached stacks (from thread termination) will be returned to base0 and made
available for reuse, but no merging will be attempted since they were bump
allocated out of base blocks. These reused base extents are managed using
separately allocated base edata_t -- they are cached in base->edata_avail when
the extent is all allocated.

One tricky part is, stats updating must be skipped for such reused extents
(since they were accounted for already, and there is no purging for base). This
requires tracking the "if is reused" state explicitly and bypass the stats
updates when allocating from them.
This commit is contained in:
Qi Wang
2023-09-13 21:51:54 -07:00
committed by Qi Wang
parent a442d9b895
commit 72cfdce718
7 changed files with 202 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
test/unit/tcache_max.c
View File

@@ -215,6 +215,29 @@ tcache_max2nhbins(size_t tcache_max) {
return sz_size2index(tcache_max) + 1;
}
static void
validate_tcache_stack(tcache_t *tcache) {
/* Assume bins[0] is enabled. */
void *tcache_stack = tcache->bins[0].stack_head;
bool expect_found = cache_bin_stack_use_thp() ? true : false;
/* Walk through all blocks to see if the stack is within range. */
base_t *base = b0get();
base_block_t *next = base->blocks;
bool found = false;
do {
base_block_t *block = next;
if ((byte_t *)tcache_stack >= (byte_t *)block &&
(byte_t *)tcache_stack < ((byte_t *)block + block->size)) {
found = true;
break;
}
next = block->next;
} while (next != NULL);
expect_true(found == expect_found, "Unexpected tcache stack source");
}
static void *
tcache_check(void *arg) {
size_t old_tcache_max, new_tcache_max, min_tcache_max, sz;
@@ -235,6 +258,7 @@ tcache_check(void *arg) {
tcache_nhbins = tcache_nhbins_get(tcache);
expect_zu_eq(tcache_nhbins, (size_t)global_do_not_change_nhbins,
"Unexpected default value for tcache_nhbins");
validate_tcache_stack(tcache);
/*
* Close the tcache and test the set.
@@ -280,6 +304,7 @@ tcache_check(void *arg) {
"Unexpected.mallctl().failure");
expect_zu_eq(old_tcache_max, min_tcache_max,
"Unexpected value for tcache_max");
validate_tcache_stack(tcache);
/*
* Check the thread's tcache_max and nhbins both through mallctl
@@ -303,6 +328,7 @@ tcache_check(void *arg) {
test_tcache_max_impl(new_tcache_max,
alloc_option, dalloc_option);
}
validate_tcache_stack(tcache);
}
return NULL;