On Thu 16-03-17 02:23:18, l...@pengaru.com wrote: > On Thu, Mar 16, 2017 at 10:08:44AM +0100, Michal Hocko wrote: > > On Thu 16-03-17 01:47:33, l...@pengaru.com wrote: > > [...] > > > While on the topic of understanding allocation stalls, Philip Freeman > > > recently > > > mailed linux-kernel with a similar report, and in his case there are > > > plenty of > > > page cache pages. It was also a GFP_HIGHUSER_MOVABLE 0-order allocation. > > > > care to point me to the report? > > http://lkml.iu.edu/hypermail/linux/kernel/1703.1/06360.html
Thanks. It is gone from my lkml mailbox. Could you CC me (and linux-mm) please? > > > > > I'm no MM expert, but it appears a bit broken for such a low-order > > > allocation > > > to stall on the order of 10 seconds when there's plenty of reclaimable > > > pages, > > > in addition to mostly unused and abundant swap space on SSD. > > > > yes this might indeed signal a problem. > > Well maybe I missed something obvious that a better informed eye will catch. Nothing really obvious. There is indeed a lot of anonymous memory to swap out. Almost no pages on file LRU lists (active_file:759 inactive_file:749) but 158783 total pagecache pages so we have to have a lot of pages in the swap cache. I would probably have to see more data to make a full picture. -- Michal Hocko SUSE Labs
