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A.1. Performance Patches from Google

Innobase Oy gratefully acknowledges the following contributions from Google, Inc. to improve InnoDB performance:

  • Replacing InnoDB’s use of Pthreads mutexes with calls to GCC atomic builtins, as discussed in Section 7.2, “Faster Locking for Improved Scalability”. This change means that InnoDB mutex and and rw-lock operations take less CPU time, and improves throughput on those platforms where the atomic operations are available.

  • Controlling master thread I/O rate, as discussed in Section 7.10, “Controlling the Master Thread I/O Rate”. The master thread in InnoDB is a thread that performs various tasks in the background. Historically, InnoDB has used a hard coded value as the total I/O capacity of the server. With this change, user can control the number of I/O operations that can be performed per second based on their own workload.

Changes from the Google contributions were incorporated in the following source code files: btr0cur.c, btr0sea.c, buf0buf.c, buf0buf.ic, ha_innodb.cc, log0log.c, log0log.h, os0sync.h, row0sel.c, srv0srv.c, srv0srv.h, srv0start.c, sync0arr.c, sync0rw.c, sync0rw.h, sync0rw.ic, sync0sync.c, sync0sync.h, sync0sync.ic, and univ.i.

These contributions are incorporated subject to the conditions contained in the file COPYING.Google, which are reproduced here.

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This is the User’s Guide for InnoDB Plugin 1.0.6 for MySQL 5.1, generated on March 4, 2010 (rev 673:680M).