On Wed, Jul 13, 2016 at 11:00:03AM +0100, Mel Gorman wrote: > From: Minchan Kim <[email protected]> > > Note from Mel: This may optionally be considered a fix to the mmotm patch > mm-page_alloc-consider-dirtyable-memory-in-terms-of-nodes.patch > but if so, please preserve credit for Minchan. > > When I tested vmscale in mmtest in 32bit, I found the benchmark was slow > down 0.5 times. > > base node > 1 global-1 > User 12.98 16.04 > System 147.61 166.42 > Elapsed 26.48 38.08 > > With vmstat, I found IO wait avg is much increased compared to base. > > The reason was highmem_dirtyable_memory accumulates free pages and > highmem_file_pages from HIGHMEM to MOVABLE zones which was wrong. With > that, dirth_thresh in throtlle_vm_write is always 0 so that it calls > congestion_wait frequently if writeback starts. > > With this patch, it is much recovered. > > base node fi > 1 global-1 fix > User 12.98 16.04 13.78 > System 147.61 166.42 143.92 > Elapsed 26.48 38.08 29.64 > > Signed-off-by: Minchan Kim <[email protected]> > Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
