tree eadc35b70c0169096a7dbaf4eb9966be7630db04
parent c90821a26a8c90ad1e3116393b8a8260ab46bffb
author Dave Chinner <dchinner@redhat.com> 1292806997 +1100
committer Dave Chinner <david@fromorbit.com> 1292806997 +1100

xfs: remove all the inodes on a buffer from the AIL in bulk

When inode buffer IO completes, usually all of the inodes are removed from the
AIL. This involves processing them one at a time and taking the AIL lock once
for every inode. When all CPUs are processing inode IO completions, this causes
excessive amount sof contention on the AIL lock.

Instead, change the way we process inode IO completion in the buffer
IO done callback. Allow the inode IO done callback to walk the list
of IO done callbacks and pull all the inodes off the buffer in one
go and then process them as a batch.

Once all the inodes for removal are collected, take the AIL lock
once and do a bulk removal operation to minimise traffic on the AIL
lock.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>