Mel, I tend to agree with the whole patchset except for this one. The worry comes from the fact that there are always the very possible unevenly distribution of dirty pages throughout the LRU lists. This patch works on local information and may unnecessarily throttle page reclaim when running into small spans of dirty pages. One possible scheme of global throttling is to first tag the skipped page with PG_reclaim (as you already do). And to throttle page reclaim only when running into pages with both PG_dirty and PG_reclaim set, which means we have cycled through the _whole_ LRU list (which is the global and adaptive feedback we want) and run into that dirty page for the second time. One test scheme would be to read/write a sparse file fast with some average 5:1 or 10:1 or whatever read:write ratio. This can effectively spread dirty pages all over the LRU list. It's a practical test since it mimics the typical file server workload with concurrent downloads and uploads. Thanks, Fengguang _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
