Bug #58766 | Server binary was compiled without fast-mutexes | ||
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Submitted: | 6 Dec 2010 22:48 | Modified: | 29 Jan 2014 0:51 |
Reporter: | Alexey Stroganov | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server | Severity: | S2 (Serious) |
Version: | 5.5.8 | OS: | Any (Linux) |
Assigned to: | Assigned Account | CPU Architecture: | Any |
[6 Dec 2010 22:48]
Alexey Stroganov
[7 Dec 2010 11:43]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/126190 3169 Jonathan Perkin 2010-12-07 bug#58766: Server binary was compiled without fast-mutexes Re-enable fast mutexes on Linux for release builds.
[7 Dec 2010 11:50]
Davi Arnaut
I suggest holding on this a bit, the performance implications are not clear.
[7 Dec 2010 11:57]
Davi Arnaut
I've run some trace data and the the "fast" mutexes only help a bit in the very contented cases where the lock is hold for somewhat large periods, but it causes a equivalent slowdown for cases where the lock is held for brief periods. This happens because of the way it spins on the lock, which is somewhat long and does not adapt to the lock. If the lock is being held for long periods, it helps a bit because the contention on the lock will be reduced. If the lock is held for brief periods, it will cause a slowdown because it will spin while the lock could have been acquired.
[17 Dec 2010 12:53]
Bugs System
Pushed into mysql-5.5 5.5.9 (revid:georgi.kodinov@oracle.com-20101217124733-p1ivu6higouawv8l) (version source revid:jonathan.perkin@oracle.com-20101207114038-af8vvh6e3cx9x1sx) (merge vers: 5.5.8) (pib:24)
[17 Dec 2010 12:57]
Bugs System
Pushed into mysql-trunk 5.6.1 (revid:georgi.kodinov@oracle.com-20101217125013-y8pb3az32rtbplc9) (version source revid:anitha.gopi@sun.com-20101210041312-50t9adyhwwybsm6x) (merge vers: 5.6.1) (pib:24)
[29 Jan 2014 0:51]
Paul DuBois
Noted in 5.5.9 changelog. Release builds on Linux now are compiled with WITH_FAST_MUTEXES enabled.