On Wed, Apr 06, 2011 at 02:33:56PM -0400, Christoph Hellwig wrote: > The patch looks correct, but I wonder what the performance implications > of flushing the AIL every 30 seconds are. Did you benchmark the > patchset to see what it does to performance numbers for metadata > intensive workloads? In my measurements it's made no difference. If the workload is being sustained for more than a few seconds, then memory reclaim typically becomes active and the push from there becomes the dominating factor. This effectively makes the syncd work trigger a no-op. If the push from the syncd work does trigger work to be done, it's generally because the filesystem has gone to idle or only has a low level of modifications being done. In either case, it doesn't affect performance, especially with delaylog pinning the working set of metadata in memory... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
