From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f182.google.com (mail-lb0-f182.google.com [209.85.217.182]) by kanga.kvack.org (Postfix) with ESMTP id 758146B0038 for ; Fri, 14 Aug 2015 09:26:51 -0400 (EDT) Received: by lbbpu9 with SMTP id pu9so45477445lbb.3 for ; Fri, 14 Aug 2015 06:26:50 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id f8si10061414wjr.70.2015.08.14.06.26.48 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 14 Aug 2015 06:26:49 -0700 (PDT) Subject: Re: [PATCH] mm: make page pfmemalloc check more robust References: <1439456364-4530-1-git-send-email-mhocko@kernel.org> <55CC5FA0.300@suse.cz> <1439476856.7960.8.camel@edumazet-glaptop2.roam.corp.google.com> From: Vlastimil Babka Message-ID: <55CDEC95.5050307@suse.cz> Date: Fri, 14 Aug 2015 15:26:45 +0200 MIME-Version: 1.0 In-Reply-To: <1439476856.7960.8.camel@edumazet-glaptop2.roam.corp.google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: mhocko@kernel.org, linux-mm@kvack.org, Mel Gorman , Jiri Bohac , Andrew Morton , "David S. Miller" , LKML , netdev@vger.kernel.org, Michal Hocko On 08/13/2015 04:40 PM, Eric Dumazet wrote: > On Thu, 2015-08-13 at 11:13 +0200, Vlastimil Babka wrote: > >> Given that this apparently isn't the first case of this localhost issue, >> I wonder if network code should just clear skb->pfmemalloc during send >> (or maybe just send over localhost). That would be probably easier than >> distinguish the __skb_fill_page_desc() callers for send vs receive. > > Would this still needed after this patch ? Not until another corner case is discovered :) Or something passes a genuine pfmemalloc page to a socket (sending contents of some slab objects perhaps, where the slab page was allocated as pfmemalloc? Dunno if that can happen right now). > It is sad we do not have a SNMP counter to at least count how often we > drop skb because pfmemalloc is set. > > I'll provide such a patch. > > -- 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