Hi Sergey, I looked into fast mutex in the past [1] and was never able to get a straight answer (even from the original developer) on what was the intention behind it and how it made things faster as it actually made things slower in the past (Bug#38941, others). There is a comment in http://bugs.mysql.com/bug.php?id=58766 highlighting one case where I saw a small performance improvement, but even that was highly workload/hardware dependent (can't recall which workload exactly, might have been sysbench's point select or something similar).
1. http://dev.mysql.com/worklog/task/?id=4601 On Wed, Feb 26, 2014 at 10:36 PM, Sergey Vojtovich <s...@mariadb.org> wrote: > Hi Sergei, > > do you know if we ship any binaries with fast mutex > (-DMY_PTHREAD_FASTMUTEX) > enabled or officially suggest it? What was it's intention and what loads > it was > supposed to make faster? > > I'm trying to understand if fastmutex is worth fixing. It looks like > duplication > of PTHREAD_MUTEX_ADAPTIVE_NP, so we have double spinning when they're > enabled. > According to my recent benchmarks it shown worst performance. > > Thanks, > Sergey > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-developers > Post to : maria-developers@lists.launchpad.net > Unsubscribe : https://launchpad.net/~maria-developers > More help : https://help.launchpad.net/ListHelp >
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