From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mel Gorman Subject: Re: ppoll() stuck on POLLIN while TCP peer is sending Date: Wed, 9 Jan 2013 13:37:46 +0000 Message-ID: <20130109133746.GD13304@suse.de> References: <20121228014503.GA5017@dcvr.yhbt.net> <20130102200848.GA4500@dcvr.yhbt.net> <20130104160148.GB3885@suse.de> <20130106120700.GA24671@dcvr.yhbt.net> <20130107122516.GC3885@suse.de> <20130107223850.GA21311@dcvr.yhbt.net> <20130108224313.GA13304@suse.de> <20130108232325.GA5948@dcvr.yhbt.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Cc: linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Rik van Riel , Minchan Kim , Eric Dumazet , Andrew Morton , Linus Torvalds To: Eric Wong Return-path: Content-Disposition: inline In-Reply-To: <20130108232325.GA5948@dcvr.yhbt.net> Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org On Tue, Jan 08, 2013 at 11:23:25PM +0000, Eric Wong wrote: > Mel Gorman 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). > page->pfmemalloc can be left set for captured pages so try this but as capture is rarely used I'm strongly favouring a partial revert even if this works for you. I haven't reproduced this using your workload yet but I have found that high-order allocation stress tests for 3.8-rc2 are completely screwed. 71% success rates at rest in 3.7 and 6% in 3.8-rc2 so I have to chase that down too. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9d20c13..c242d21 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2180,8 +2180,10 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, current->flags &= ~PF_MEMALLOC; /* If compaction captured a page, prep and use it */ - if (page && !prep_new_page(page, order, gfp_mask)) + if (page && !prep_new_page(page, order, gfp_mask)) { + page->pfmemalloc = false; goto got_page; + } if (*did_some_progress != COMPACT_SKIPPED) { /* Page migration frees to the PCP lists but we want merging */ -- 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: email@kvack.org