Re: [Maria-developers] Rev 4033: MDEV-5766 - my_atomic_load does memory writes

Hi, Sergey! On Mar 07, Sergey Vojtovich wrote:

revno: 4033 revision-id: svoj@mariadb.org-20140307074306-i3l4fllu2rj5pouf parent: svoj@mariadb.org-20140306121912-i1p8iilpsgc8m4bn committer: Sergey Vojtovich <svoj@mariadb.org> branch nick: 10.0 timestamp: Fri 2014-03-07 11:43:06 +0400 message: MDEV-5766 - my_atomic_load does memory writes

my_atomic_load() is implemented as __sync_fetch_and_or(var, 0) which writes or-ed value back to var. Memory writes as such have worse performance and scalability than reads.

gcc 4.7 and up offers better facility for atomic loads/stores. Use it whenever it is available.

Thanks. ok to push Regards, Sergei