On Mon 30-01-17 09:55:46, Michal Hocko wrote:

On Sun 29-01-17 00:27:27, Tetsuo Handa wrote:

[...]

quoted

Regarding [1], it helped avoiding the too_many_isolated() issue. I can't
tell whether it has any negative effect, but I got on the first trial that
all allocating threads are blocked on wait_for_completion() from flush_work()
in drain_all_pages() introduced by "mm, page_alloc: drain per-cpu pages from
workqueue context". There was no warn_alloc() stall warning message afterwords.

That patch is buggy and there is a follow up [1] which is not sitting in the
mmotm (and thus linux-next) yet. I didn't get to review it properly and
I cannot say I would be too happy about using WQ from the page
allocator. I believe even the follow up needs to have WQ_RECLAIM WQ.

[1] http://lkml.kernel.org/r/20170125083038.rzb5f43nptmk7aed@techsingularity.net

Did you get chance to test with this follow up patch? It would be
interesting to see whether OOM situation can still starve the waiter.
The current linux-next should contain this patch.

Thanks!
-- 
Michal Hocko
SUSE Labs

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>