Bug #56791 | Remove ios_mutex from InnoDB code | ||
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Submitted: | 15 Sep 2010 10:32 | Modified: | 9 Dec 2010 22:44 |
Reporter: | Jimmy Yang | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: InnoDB storage engine | Severity: | S3 (Non-critical) |
Version: | 5.5 | OS: | Any |
Assigned to: | Jimmy Yang | CPU Architecture: | Any |
[15 Sep 2010 10:32]
Jimmy Yang
[15 Sep 2010 15:30]
MySQL Verification Team
Thank you for the bug report.
[21 Sep 2010 16:58]
Omer Barnir
triage: setting to SRMRTBD (code cleanup)
[21 Oct 2010 12:34]
Marko Mäkelä
The variable "ios" that is protected by "ios_mutex" is completely unused. It a static variable in srv0start.c that is only initialized or incremented, never read or copied. We should remove it as well. Because there is some contention on the useless ios_mutex, I think that this bug should be fixed already in 5.5, if not 5.1.
[21 Oct 2010 12:38]
Jimmy Yang
Updated a few counters in the similar situation: 1) Removed ios_mutex 2) Added generic counter operation to increment/decrement following counters atomically if HAVE_ATOMIC_BUILTINS is defined: a) ios b) dict_table_t::n_foreign_key_checks_running c) trx_sys->rseg_history_len We will fall back to mutex protection for "n_foreign_key_checks_running" and "rseg_history_len" if HAVE_ATOMIC_BUILTINS not defined.
[21 Oct 2010 12:44]
Calvin Sun
Fine with the fix in 5.1.
[21 Oct 2010 12:59]
Jimmy Yang
We will use this patch just to remove ios_mutex and ios which is a static counter not being used.
[22 Oct 2010 6:39]
Jimmy Yang
Checked in mysql-5.5-innodb.
[13 Nov 2010 16:26]
Bugs System
Pushed into mysql-trunk 5.6.99-m5 (revid:alexander.nozdrin@oracle.com-20101113155825-czmva9kg4n31anmu) (version source revid:alexander.nozdrin@oracle.com-20101113152450-2zzcm50e7i4j35v7) (merge vers: 5.6.1-m4) (pib:21)
[13 Nov 2010 16:41]
Bugs System
Pushed into mysql-next-mr (revid:alexander.nozdrin@oracle.com-20101113160336-atmtmfb3mzm4pz4i) (version source revid:alexander.nozdrin@oracle.com-20101113152540-gxro4g0v29l27f5x) (pib:21)
[16 Dec 2010 22:34]
Bugs System
Pushed into mysql-5.5 5.5.9 (revid:jonathan.perkin@oracle.com-20101216101358-fyzr1epq95a3yett) (version source revid:jonathan.perkin@oracle.com-20101216101358-fyzr1epq95a3yett) (merge vers: 5.5.9) (pib:24)