From bea0ac1d8703091294fe5822d982591c849b5458 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Thu, 16 Jul 2009 07:24:50 -0700 Subject: 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. --- malloc/malloc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'malloc/malloc.c') 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). */ -- cgit v1.2.3