project-base/server-skynet-source-3rd-jemalloc
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Sanity check szind on tcache flush.

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This adds some overhead to the tcache flush path (which is one of the
popular paths).  Guard it behind a config option.
This commit is contained in:
Qi Wang 2019-01-22 13:59:23 -08:00 committed by Qi Wang
parent b33eb26dee
commit e13400c919
3 changed files with 59 additions and 2 deletions
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16
configure.ac
View File

@ -1403,6 +1403,22 @@ if test "x$enable_readlinkat" = "x1" ; then
fi
AC_SUBST([enable_readlinkat])
dnl Avoid the extra size checking by default
AC_ARG_ENABLE([extra-size-check],
[AS_HELP_STRING([--enable-extra-size-check],
[Perform additonal size related sanity checks])],
[if test "x$enable_extra_size_check" = "xno" ; then
enable_extra_size_check="0"
else
enable_extra_size_check="1"
fi
],
[enable_extra_size_check=="0"]
)
if test "x$enable_extra_size_check" = "x1" ; then
AC_DEFINE([JEMALLOC_EXTRA_SIZE_CHECK], [ ])
fi
AC_SUBST([enable_extra_size_check])
JE_COMPILABLE([a program using __builtin_unreachable], [
void foo (void) {

3
include/jemalloc/internal/jemalloc_internal_defs.h.in
View File

@ -372,4 +372,7 @@
*/
#undef JEMALLOC_STRERROR_R_RETURNS_CHAR_WITH_GNU_SOURCE
/* Performs additional size-matching sanity checks when defined. */
#undef JEMALLOC_EXTRA_SIZE_CHECK
#endif /* JEMALLOC_INTERNAL_DEFS_H_ */

42
src/tcache.c
View File

@ -100,6 +100,34 @@ tcache_alloc_small_hard(tsdn_t *tsdn, arena_t *arena, tcache_t *tcache,
return ret;
}
/* Enabled with --enable-extra-size-check. */
#ifdef JEMALLOC_EXTRA_SIZE_CHECK
static void
tbin_extents_lookup_size_check(tsdn_t *tsdn, cache_bin_t *tbin, szind_t binind,
size_t nflush, extent_t **extents){
rtree_ctx_t rtree_ctx_fallback;
rtree_ctx_t *rtree_ctx = tsdn_rtree_ctx(tsdn, &rtree_ctx_fallback);
/*
* Verify that the items in the tcache all have the correct size; this
* is useful for catching sized deallocation bugs, also to fail early
* instead of corrupting metadata. Since this can be turned on for opt
* builds, avoid the branch in the loop.
*/
szind_t szind;
size_t sz_sum = binind * nflush;
for (unsigned i = 0 ; i < nflush; i++) {
rtree_extent_szind_read(tsdn, &extents_rtree,
rtree_ctx, (uintptr_t)*(tbin->avail - 1 - i), true,
&extents[i], &szind);
sz_sum -= szind;
}
if (sz_sum != 0) {
abort();
}
}
#endif
void
tcache_bin_flush_small(tsd_t *tsd, tcache_t *tcache, cache_bin_t *tbin,
szind_t binind, unsigned rem) {
@ -112,11 +140,16 @@ tcache_bin_flush_small(tsd_t *tsd, tcache_t *tcache, cache_bin_t *tbin,
assert(arena != NULL);
unsigned nflush = tbin->ncached - rem;
VARIABLE_ARRAY(extent_t *, item_extent, nflush);
#ifndef JEMALLOC_EXTRA_SIZE_CHECK
/* Look up extent once per item. */
for (unsigned i = 0 ; i < nflush; i++) {
item_extent[i] = iealloc(tsd_tsdn(tsd), *(tbin->avail - 1 - i));
}
#else
tbin_extents_lookup_size_check(tsd_tsdn(tsd), tbin, binind, nflush,
item_extent);
#endif
while (nflush > 0) {
/* Lock the arena bin associated with the first object. */
extent_t *extent = item_extent[0];
@ -202,11 +235,16 @@ tcache_bin_flush_large(tsd_t *tsd, cache_bin_t *tbin, szind_t binind,
assert(tcache_arena != NULL);
unsigned nflush = tbin->ncached - rem;
VARIABLE_ARRAY(extent_t *, item_extent, nflush);
#ifndef JEMALLOC_EXTRA_SIZE_CHECK
/* Look up extent once per item. */
for (unsigned i = 0 ; i < nflush; i++) {
item_extent[i] = iealloc(tsd_tsdn(tsd), *(tbin->avail - 1 - i));
}
#else
tbin_extents_lookup_size_check(tsd_tsdn(tsd), tbin, binind, nflush,
item_extent);
#endif
while (nflush > 0) {
/* Lock the arena associated with the first object. */
extent_t *extent = item_extent[0];