From: Marc Alff Date: July 22 2010 12:58am Subject: bzr commit into mysql-trunk-bugfixing branch (marc.alff:3133) Bug#55462 List-Archive: http://lists.mysql.com/commits/114105 X-Bug: 55462 Message-Id: <20100722005834.D672045E80@linux-su11.site> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1290097490127271569==" --===============1290097490127271569== MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline #At file:///home/malff/BZR_TREE/mysql-trunk-bugfixing-55462/ based on revid:jonathan.perkin@stripped 3133 Marc Alff 2010-07-21 Bug#55462 Performance schema: reduce the overhead of PFS_events_waits::m_wait_class This is a performance improvement fix. Removed the "volatile" property of PFS_events_waits::m_wait_class. Simplified the code accordingly. modified: storage/perfschema/pfs.cc storage/perfschema/pfs_events_waits.cc storage/perfschema/pfs_events_waits.h storage/perfschema/table_events_waits.cc === modified file 'storage/perfschema/pfs.cc' --- a/storage/perfschema/pfs.cc 2010-07-15 23:44:45 +0000 +++ b/storage/perfschema/pfs.cc 2010-07-22 00:58:31 +0000 @@ -1117,7 +1117,6 @@ get_thread_mutex_locker_v1(PSI_mutex_loc } PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_mutex= pfs_mutex; pfs_locker->m_waits_current.m_thread= pfs_thread; @@ -1163,7 +1162,6 @@ get_thread_rwlock_locker_v1(PSI_rwlock_l } PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_rwlock= pfs_rwlock; pfs_locker->m_waits_current.m_thread= pfs_thread; @@ -1222,7 +1220,6 @@ get_thread_cond_locker_v1(PSI_cond_locke } PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_cond= pfs_cond; pfs_locker->m_waits_current.m_thread= pfs_thread; @@ -1267,7 +1264,6 @@ get_thread_table_locker_v1(PSI_table_loc } PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_table= pfs_table; pfs_locker->m_waits_current.m_thread= pfs_thread; @@ -1320,7 +1316,6 @@ get_thread_file_name_locker_v1(PSI_file_ PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_file= pfs_file; pfs_locker->m_waits_current.m_thread= pfs_thread; @@ -1372,7 +1367,6 @@ get_thread_file_stream_locker_v1(PSI_fil } PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_file= pfs_file; pfs_locker->m_waits_current.m_thread= pfs_thread; @@ -1441,7 +1435,6 @@ get_thread_file_descriptor_locker_v1(PSI } PFS_wait_locker *pfs_locker= &pfs_thread->m_wait_locker_stack [pfs_thread->m_wait_locker_count]; - pfs_locker->m_waits_current.m_wait_class= NO_WAIT_CLASS; pfs_locker->m_target.m_file= pfs_file; pfs_locker->m_waits_current.m_thread= pfs_thread; === modified file 'storage/perfschema/pfs_events_waits.cc' --- a/storage/perfschema/pfs_events_waits.cc 2010-07-15 23:44:45 +0000 +++ b/storage/perfschema/pfs_events_waits.cc 2010-07-22 00:58:31 +0000 @@ -81,26 +81,10 @@ void cleanup_events_waits_history_long(v events_waits_history_long_array= NULL; } -static void copy_events_waits(PFS_events_waits *dest, - const PFS_events_waits *source) +static inline void copy_events_waits(PFS_events_waits *dest, + const PFS_events_waits *source) { - /* m_wait_class must be the first member of PFS_events_waits. */ - compile_time_assert(offsetof(PFS_events_waits, m_wait_class) == 0); - - char* dest_body= (reinterpret_cast (dest)) + sizeof(events_waits_class); - const char* source_body= (reinterpret_cast (source)) - + sizeof(events_waits_class); - - /* See comments in table_events_waits_common::make_row(). */ - - /* Signal readers they are about to read garbage ... */ - dest->m_wait_class= NO_WAIT_CLASS; - /* ... that this can generate. */ - memcpy_fixed(dest_body, - source_body, - sizeof(PFS_events_waits) - sizeof(events_waits_class)); - /* Signal readers the record is now clean again. */ - dest->m_wait_class= source->m_wait_class; + memcpy_fixed(dest, source, sizeof(PFS_events_waits)); } /** @@ -118,9 +102,7 @@ void insert_events_waits_history(PFS_thr causing a potential race condition. We are not testing for this and insert a possibly empty record, to make this thread (the writer) faster. - This is ok, the truncated data will have - wait->m_wait_class == NO_WAIT_CLASS, - which readers of m_waits_history will filter out. + This is ok, the readers of m_waits_history will filter this out. */ copy_events_waits(&thread->m_waits_history[index], wait); === modified file 'storage/perfschema/pfs_events_waits.h' --- a/storage/perfschema/pfs_events_waits.h 2010-07-15 23:44:45 +0000 +++ b/storage/perfschema/pfs_events_waits.h 2010-07-22 00:58:31 +0000 @@ -97,7 +97,7 @@ struct PFS_events_waits - TRUNCATE EVENTS_WAITS_HISTORY - TRUNCATE EVENTS_WAITS_HISTORY_LONG */ - volatile events_waits_class m_wait_class; + events_waits_class m_wait_class; /** Executing thread. */ PFS_thread *m_thread; /** Instrument metadata. */ === modified file 'storage/perfschema/table_events_waits.cc' --- a/storage/perfschema/table_events_waits.cc 2010-07-16 00:06:33 +0000 +++ b/storage/perfschema/table_events_waits.cc 2010-07-22 00:58:31 +0000 @@ -217,16 +217,8 @@ void table_events_waits_common::make_row or 8 atomics per recorded event. The problem is that we record a *lot* of events ... - Instead, a *dirty* marking is done using m_wait_class. - Using m_wait_class alone does not guarantee anything, it just filters - out most of the bad data. - This is acceptable because this code is garbage-proof, - and won't crash on bad data, only display it, - very rarely (which is accepted). - - If a bad record is displayed, it's a very transient failure: - the next select * from EVENTS_WAITS_CURRENT/_HISTORY/_HISTORY_LONG will - show clean data again. + This code is prepared to accept *dirty* records, + and sanitizes all the data before returning a row. */ m_row.m_thread_internal_id= safe_thread->m_thread_internal_id; --===============1290097490127271569== MIME-Version: 1.0 Content-Type: text/bzr-bundle; charset="us-ascii"; name="bzr/marc.alff@stripped" Content-Transfer-Encoding: 7bit Content-Disposition: inline # Bazaar merge directive format 2 (Bazaar 0.90) # revision_id: marc.alff@stripped # target_branch: file:///home/malff/BZR_TREE/mysql-trunk-bugfixing-\ # 55462/ # testament_sha1: 585f7b3bcbef9e6a7f42b8ff1bc9cd2ed420ea72 # timestamp: 2010-07-21 18:58:34 -0600 # base_revision_id: jonathan.perkin@stripped\ # gqyrtmkgwrjfgsmc # # Begin bundle IyBCYXphYXIgcmV2aXNpb24gYnVuZGxlIHY0CiMKQlpoOTFBWSZTWe85iIIAA6dfgEAQeHf//3MC XAC////wYAaTnc+AB6O83exPT3ZdNdGEkkNTBGjKn41TxTJtJpinkgADRoEpGpqenpSeUflNMptQ AAGgDIABkIaSPUelD1HqeoaAAGmRkAAEiRE00m0aJkeoAAGjQ0NAAOYBMAJgABMAATAAEkQJoAE1 U9qeJT0eqDT1NGjRoNNG1Jqmx70nS7dxIm0qaobbmYxWS5xyPreW6IuyynY4CEMVjJqqgSOIM2S2 UahbRVlRAUHDh2mvN8OwDSFgNNgNtg/XyFivTqaxNYnQwk4eVztqUrXaRlprqqov1DdcUuV532eN mGCePVdll4RGqM7DXXr/Z05JhkyWYASeJl8xApBYdHWrERm3IIABhWELINix3i7C8wjrPu02AYMD 48ZeqUjJBTjfDZHT3yZ2SKLJ7ZVAYAxYMH5SDwcXa3FYKW8FBb6aNeUi9ZPWt+VOCAig2BDK9bg1 IhMMQkIsY7sHZkoMiTMdWQpAoukDreLpJRBRcF6ipMjNlNhgA0mCdUK2impGKYnamj2BT+owFcyu b3BFGIKxw9ci0FRkg9kOo3yOZnW6SsBMZl5OjoUUWz8t99t7vKNfgzMMGgmca0F88YzRxfwQ5aEN qP7px87PusItVlkGJ5AtdjocFTmfRXamzUg2WMAWi2SSgCzI9Y2XxoChQyd5Yl60LwVRqkikDNzv UI0sMdpXIsSubmRq7kHqVnSZc5MFLCwsOb3lhf2joY41XRMSvN3z369jgnaxdtcCtSJA0tmH4vUF I5TgjIpFgTZw3ImCNSFMGk+F2sIj3Kazw1aa6hF8SNEe/PRXHFSkAVhapAtDc2NZmxuUvGsNzYNb P+v0jfCbOzRi7FH7cqIXPguW5rTIPbNHLhSjZ7wGIFw+pKAnKCWJKL8I0ey0DZkk5PKGdCRPnbUj pbxrhI0fUVDMqZxMbbjwoX5zBSdZNcRKspYWmAX7lhMc42BQm2jXvCFb7wTUUiMTEtI5lqWFg/GR Cpqxdl7gVRzFSo0zziyDWpsJjuSam4ORSJCSQFJo5ESXmmLszkyXZsDTXQGREm22Pc1BouClNCv0 laY2ma80vdEedLap9kPsbx5GfJ3PApiglFlAUJEu+QGagAM9w4eJIRyH7HBz5ECB4nSsB/S9dcD3 /iCE+EtHgyUgieAIdaAd8rwsvSZXolf8wQCYLkDi2hOoj5+Rauh7RxNlCBicGIiS7GxP7ZgiGGpX eQDnUYcJICsliY5eY/wBSNtpnnp3NjNJzAvMuh6aH5KR2NyT1hTl5Iuf6A4I9RiCM/lCvO+r2XOH B0BeBYdMrCFaFRcigpkODqqILSgavg/FQJw/Hnld1BcUbXtVvBQo52McQhFESxF0jhgFcOFDhaNn G4tJrzuNJ1DaHiVscmdrSoSrqEplFwVfPcb0S3j4nTPfhK3BH91FSNuv4uUhiQEBvSd8I3bfkwaO Lk9h908Y0+tdEl5RJUoJO/eDSmRuIbzs9INxljKRo35zjkBYj/LwBO/gZhaK7x4Z9xQdO+gkEUaX cCtwppTzqjQtlfC0rnOURxgWWTRAF6Jt/aC4Qcr0iQ1XbH2ZVQNOe6On6KIRYD6M4+uBaI0VafOh /x23aL0nvtTM3VJ2S2AqXIDpWpkVV3rUqJAWEKHTrQoJTn6wCZKLeoglCfwQ4IYPNMHpqgO+Txbw 75/WCljjgCNzmZosIA+BrIQBc0DcZVAmsqC/A07ZTchw9WZ4lCFKWAygEAHYO98dYytQOwkMuuFw Ka5lblZ1dooRVL2r3wom9ARck5eLpAMdy/ars747ODCiQ68OalHQYZhmkos0StHNLq7acFe8HpC3 RCCgguVxFmSMHw7OioHr9idZ2ou5TtVlD4qj+qkA0glNqW1Cmc84LmDGiHAmIIvyB3sa4GsIVSYJ cAqit4XxllyC/uy4wSwa0FtTSxht/EFGxRD2gQ7diwj69tAHonRUEz825tmSgpVSvZl4SQEoCQ+0 DU/nx6Rkq4GTXJi5SAHZLrhrHqCItoLJbOIJiZBq0szWtgawXJVXzJTcwX/F3JFOFCQ7zmIggA== --===============1290097490127271569==--