| commit | 5a9c8c05a5a0cdced4122589184fd795b761bb4a | [log] [tgz] |
|---|---|---|
| author | Rich Felker <dalias@aerifal.cx> | Sun Aug 16 18:15:18 2015 +0000 |
| committer | Rich Felker <dalias@aerifal.cx> | Sun Aug 16 18:15:18 2015 +0000 |
| tree | 34b9f909c151de0d24ec29ef194815a5fa4daede | |
| parent | c13f2af1fe1856e36dd1b2773cac05d5d72641dc [diff] |
mitigate performance regression in libc-internal locks on x86_64 commit 3c43c0761e1725fd5f89a9c028cbf43250abb913 fixed missing synchronization in the atomic store operation for i386 and x86_64, but opted to use mfence for the barrier on x86_64 where it's always available. however, in practice mfence is significantly slower than the barrier approach used on i386 (a nop-like lock orl operation). this commit changes x86_64 (and x32) to use the faster barrier.