On Wed, 2020-01-08 at 14:38 +0100, David Hildenbrand wrote: > On 03.01.20 22:16, Alexander Duyck wrote: > > From: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> > > > > Rather than walking over the same pages again and again to get to the pages > > that have yet to be reported we can save ourselves a significant amount of > > time by simply rotating the list so that when we have a full list of > > reported pages the head of the list is pointing to the next non-reported > > page. Doing this should save us some significant time when processing each > > free list. > > > > This doesn't gain us much in the standard case as all of the non-reported > > pages should be near the top of the list already. However in the case of > > page shuffling this results in a noticeable improvement. Below are the > > will-it-scale page_fault1 w/ THP numbers for 16 tasks with and without > > this patch. > > > > Without: > > tasks processes processes_idle threads threads_idle > > 16 8093776.25 0.17 5393242.00 38.20 > > > > With: > > tasks processes processes_idle threads threads_idle > > 16 8283274.75 0.17 5594261.00 38.15 > > > > Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> > > --- > > mm/page_reporting.c | 30 ++++++++++++++++++++++-------- > > 1 file changed, 22 insertions(+), 8 deletions(-) > > Just a minor comment while scanning over the patches (will do more > review soon), you might want to switch to "mm/page_reporting: " styled > subjects for these optimizations. > Okay, I will update if needed for the next version.
