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

Optimize for prof_active off

Browse Source 
Move the handling of `prof_active` off case completely to slow path,
so as to reduce register pressure on malloc fast path.
This commit is contained in:
Yinan Zhang 2019-08-26 14:41:32 -07:00
parent 49e6fbce78
commit adce29c885
1 changed files with 27 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/jemalloc.c
View File

@ -2109,6 +2109,20 @@ imalloc_body(static_opts_t *sopts, dynamic_opts_t *dopts, tsd_t *tsd) {
/* If profiling is on, get our profiling context. */
if (config_prof && opt_prof) {
/*
* The fast path modifies bytes_until_sample regardless of
* prof_active. We reset it to be the sample interval, so that
* there won't be excessive routings to the slow path, and that
* when prof_active is turned on later, the counting for
* sampling can immediately resume as normal (though the very
* first sampling interval is not randomized).
*/
if (unlikely(tsd_bytes_until_sample_get(tsd) < 0) &&
!prof_active_get_unlocked()) {
tsd_bytes_until_sample_set(tsd,
(ssize_t)(1 << lg_prof_sample));
}
prof_tctx_t *tctx = prof_alloc_prep(
tsd, usize, prof_active_get_unlocked(), true);
@ -2131,6 +2145,16 @@ imalloc_body(static_opts_t *sopts, dynamic_opts_t *dopts, tsd_t *tsd) {
}
prof_malloc(tsd_tsdn(tsd), allocation, usize, &alloc_ctx, tctx);
} else {
assert(!opt_prof);
/*
* The fast path modifies bytes_until_sample regardless of
* opt_prof. We reset it to a huge value here, so as to
* minimize the triggering for slow path.
*/
if (config_prof &&
unlikely(tsd_bytes_until_sample_get(tsd) < 0)) {
tsd_bytes_until_sample_set(tsd, SSIZE_MAX);
}
allocation = imalloc_no_sample(sopts, dopts, tsd, size, usize,
ind);
if (unlikely(allocation == NULL)) {
@ -2339,16 +2363,10 @@ je_malloc(size_t size) {
if (unlikely(bytes_until_sample < 0)) {
/*
* Avoid a prof_active check on the fastpath.
* If prof_active is false, set bytes_until_sample to
* sampling interval. If prof_active is set to true,
* bytes_until_sample will be reset.
* If prof_active is false, bytes_until_sample will be
* reset in slow path.
*/
if (!prof_active_get_unlocked()) {
tsd_bytes_until_sample_set(tsd,
((uint64_t)1U << lg_prof_sample));
} else {
return malloc_default(size);
}
return malloc_default(size);
}
}