[PATCH 7/9] xfs: push the AIL from memory reclaim and periodic sync

[Alex Elder]

On Thu, 2011-04-07 at 11:57 +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> When we are short on memory, we want to expedite the cleaning of
> dirty objects.  Hence when we run short on memory, we need to kick
> the AIL flushing into action to clean as many dirty objects as
> quickly as possible.  To implement this, sample the lsn of the log
> item at the head of the AIL and use that as the push target for the
> AIL flush.
> 
> Further, we keep items in the AIL that are dirty that are not
> tracked any other way, so we can get objects sitting in the AIL that
> don't get written back until the AIL is pushed. Hence to get the
> filesystem to the idle state, we might need to push the AIL to flush
> out any remaining dirty objects sitting in the AIL. This requires
> the same push mechanism as the reclaim push.
> 
> This patch also renames xfs_trans_ail_tail() to xfs_ail_min_lsn() to
> match the new xfs_ail_max_lsn() function introduced in this patch.
> Similarly for xfs_trans_ail_push -> xfs_ail_push.
> 
> Signed-off-by: Dave Chinner <dchinner at redhat.com>

Looks OK to me.

Reviewed-by: Alex Elder <aelder at sgi.com>