On Thu, 2011-04-07 at 11:57 +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@xxxxxxxxxx> > > On of the problems with the current inode flush at ENOSPC is that we > queue a flush per ENOSPC event, regardless of how many are already > queued. Thi can result in hundreds of queued flushes, most of > which simply burn CPU scanned and do no real work. This simply slows > down allocation at ENOSPC. > > We really only need one active flush at a time, and we can easily > implement that via the new xfs_syncd_wq. All we need to do is queue > a flush if one is not already active, then block waiting for the > currently active flush to complete. The result is that we only ever > have a single ENOSPC inode flush active at a time and this greatly > reduces the overhead of ENOSPC processing. > > On my 2p test machine, this results in tests exercising ENOSPC > conditions running significantly faster - 042 halves execution time, > 083 drops from 60s to 5s, etc - while not introducing test > regressions. > > This allows us to remove the old xfssyncd threads and infrastructure > as they are no longer used. Looks good. You got rid of a useless log force as well. Reviewed-by: Alex Elder <aelder@xxxxxxx> > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
