prof: Fix memory regression

The diff 'refactor prof accum...' moved the bytes_until_sample
subtraction before the load of tdata.  If tdata is null,
tdata_get(true) will overwrite bytes_until_sample, but we
still sample the current allocation.   Instead, do the subtraction
and check logic again, to keep the previous behavior.

blame-rev: 0ac524308d
This commit is contained in:
Dave Watson 2018-10-23 08:12:46 -07:00
parent 0f8313659e
commit 936bc2aa15

View File

@ -79,15 +79,10 @@ prof_alloc_time_set(tsdn_t *tsdn, const void *ptr, alloc_ctx_t *alloc_ctx,
} }
JEMALLOC_ALWAYS_INLINE bool JEMALLOC_ALWAYS_INLINE bool
prof_sample_accum_update(tsd_t *tsd, size_t usize, bool update, prof_sample_check(tsd_t *tsd, size_t usize, bool update) {
prof_tdata_t **tdata_out) {
prof_tdata_t *tdata;
int64_t bytes_until_sample;
cassert(config_prof);
ssize_t check = update ? 0 : usize; ssize_t check = update ? 0 : usize;
bytes_until_sample = tsd_bytes_until_sample_get(tsd); int64_t bytes_until_sample = tsd_bytes_until_sample_get(tsd);
if (update) { if (update) {
bytes_until_sample -= usize; bytes_until_sample -= usize;
if (tsd_nominal(tsd)) { if (tsd_nominal(tsd)) {
@ -98,6 +93,22 @@ prof_sample_accum_update(tsd_t *tsd, size_t usize, bool update,
return true; return true;
} }
return false;
}
JEMALLOC_ALWAYS_INLINE bool
prof_sample_accum_update(tsd_t *tsd, size_t usize, bool update,
prof_tdata_t **tdata_out) {
prof_tdata_t *tdata;
cassert(config_prof);
/* Fastpath: no need to load tdata */
if (likely(prof_sample_check(tsd, usize, update))) {
return true;
}
bool booted = tsd_prof_tdata_get(tsd);
tdata = prof_tdata_get(tsd, true); tdata = prof_tdata_get(tsd, true);
if (unlikely((uintptr_t)tdata <= (uintptr_t)PROF_TDATA_STATE_MAX)) { if (unlikely((uintptr_t)tdata <= (uintptr_t)PROF_TDATA_STATE_MAX)) {
tdata = NULL; tdata = NULL;
@ -111,6 +122,15 @@ prof_sample_accum_update(tsd_t *tsd, size_t usize, bool update,
return true; return true;
} }
/*
* If this was the first creation of tdata, then
* prof_tdata_get() reset bytes_until_sample, so decrement and
* check it again
*/
if (!booted && prof_sample_check(tsd, usize, update)) {
return true;
}
if (tsd_reentrancy_level_get(tsd) > 0) { if (tsd_reentrancy_level_get(tsd) > 0) {
return true; return true;
} }