On Tue, Jan 08, 2013 at 06:32:29PM -0800, Eric Dumazet wrote: > On Tue, 2013-01-08 at 18:14 -0800, Eric Dumazet wrote: > > On Tue, 2013-01-08 at 23:23 +0000, Eric Wong wrote: > > > Mel Gorman <mgorman@xxxxxxx> wrote: > > > > Please try the following patch. However, even if it works the benefit of > > > > capture may be so marginal that partially reverting it and simplifying > > > > compaction.c is the better decision. > > > > > > I already got my VM stuck on this one. I had two twosleepy instances, > > > 2774 was the one that got stuck (also confirmed by watching top). > > > > > > Btw, have you been able to reproduce this on your end? > > > > > > I think the easiest reproduction on my 2-core VM is by running 2 > > > twosleepy processes and doing the following to dirty a lot of pages: > > > > Given the persistent sk_stream_wait_memory() traces I suspect a plain > > TCP bug, triggered by some extra wait somewhere. > > > > Please mm guys don't spend too much time right now, I'll try to > > reproduce the problem. > > > > Don't be confused by sk_stream_wait_memory() name. > > A thread is stuck here because TCP stack is failing to wake it. > > > > Hmm, it seems sk_filter() can return -ENOMEM because skb has the > pfmemalloc() set. > The skb should not have pfmemalloc set in most cases, particularly after cfd19c5a (mm: only set page->pfmemalloc when ALLOC_NO_WATERMARKS was used) but the capture patch also failed to clear pfmemalloc properly so it could be set in error. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>