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| author | Jakub Jelinek <jakub@redhat.com> | 2009-07-16 07:24:50 -0700 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2009-07-16 07:24:50 -0700 |
| commit | bea0ac1d8703091294fe5822d982591c849b5458 (patch) | |
| tree | 1d7b20d187c218c9113de06d9c295ed9039f18af /malloc | |
| parent | 55c4ce6885b577e2b29a4de674d4062a6882afe8 (diff) | |
| download | glibc-bea0ac1d8703091294fe5822d982591c849b5458.tar.gz glibc-bea0ac1d8703091294fe5822d982591c849b5458.tar.xz glibc-bea0ac1d8703091294fe5822d982591c849b5458.zip | |
Use rel semantics of cas instead of acq semantics with full barrier before it in _int_free
The following patch fixes catomic_compare_and_exchange_*_rel definitions (which were never used and weren't correct) and uses catomic_compare_and_exchange_val_rel in _int_free. Comparing to the pre-2009-07-02 --enable-experimental-malloc state the generated code should be identical on all arches other than ppc/ppc64 and on ppc/ppc64 should use lwsync instead of isync barrier.
Diffstat (limited to 'malloc')
| -rw-r--r-- | malloc/malloc.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c index 70e4e58845..0c0182ec0b 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -4822,9 +4822,8 @@ _int_free(mstate av, mchunkptr p) goto errout; } p->fd = fd = old; - atomic_full_barrier (); } - while ((old = catomic_compare_and_exchange_val_acq (fb, p, fd)) != fd); + while ((old = catomic_compare_and_exchange_val_rel (fb, p, fd)) != fd); #else /* Another simple check: make sure the top of the bin is not the record we are going to add (i.e., double free). */ |