WARNING
This patch is for mysql-5.5 only,
to be null-merged to mysql-5.6 and mysql-trunk.
This is a partial rollback of the file io instrumentation,
removing the instrumentation for mysql_file_stat in the archive engine.
See the bug comments for details.
Details:
- Archive storage engine file access were not instrumented and thus
were not shown in PS tables.
Fix:
- Added instrumentation code by using PS Apis for I/O.
