Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751606AbbKNPPc (ORCPT ); Sat, 14 Nov 2015 10:15:32 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:43610 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259AbbKNPPa (ORCPT ); Sat, 14 Nov 2015 10:15:30 -0500 Date: Sat, 14 Nov 2015 10:15:18 -0500 From: Johannes Weiner To: Vladimir Davydov Cc: David Miller , Andrew Morton , Tejun Heo , Michal Hocko , netdev@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 03/14] net: tcp_memcontrol: properly detect ancestor socket pressure Message-ID: <20151114151518.GB28175@cmpxchg.org> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> <1447371693-25143-4-git-send-email-hannes@cmpxchg.org> <20151114124552.GI31308@esperanza> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151114124552.GI31308@esperanza> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1281 Lines: 29 On Sat, Nov 14, 2015 at 03:45:52PM +0300, Vladimir Davydov wrote: > On Thu, Nov 12, 2015 at 06:41:22PM -0500, Johannes Weiner wrote: > > When charging socket memory, the code currently checks only the local > > page counter for excess to determine whether the memcg is under socket > > pressure. But even if the local counter is fine, one of the ancestors > > could have breached its limit, which should also force this child to > > enter socket pressure. This currently doesn't happen. > > > > Fix this by using page_counter_try_charge() first. If that fails, it > > means that either the local counter or one of the ancestors are in > > excess of their limit, and the child should enter socket pressure. > > > > Signed-off-by: Johannes Weiner > > Reviewed-by: Vladimir Davydov Thanks Vladimir! > For the record: it was broken by commit 3e32cb2e0a12 ("mm: memcontrol: > lockless page counters"). I didn't realize that. Fixes: 3e32cb2e0a12 ("mm: memcontrol: lockless page counters") -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/