Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030420Ab2EQUNV (ORCPT ); Thu, 17 May 2012 16:13:21 -0400 Received: from shards.monkeyblade.net ([198.137.202.13]:34656 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030403Ab2EQUNP (ORCPT ); Thu, 17 May 2012 16:13:15 -0400 Date: Thu, 17 May 2012 16:13:04 -0400 (EDT) Message-Id: <20120517.161304.1765970628771192598.davem@davemloft.net> To: mgorman@suse.de Cc: akpm@linux-foundation.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, neilb@suse.de, a.p.zijlstra@chello.nl, michaelc@cs.wisc.edu, emunson@mgebm.net Subject: Re: [PATCH 12/17] netvm: Propagate page->pfmemalloc from skb_alloc_page to skb From: David Miller In-Reply-To: <1337266231-8031-13-git-send-email-mgorman@suse.de> References: <1337266231-8031-1-git-send-email-mgorman@suse.de> <1337266231-8031-13-git-send-email-mgorman@suse.de> X-Mailer: Mew version 6.5 on Emacs 24.0.95 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Thu, 17 May 2012 13:13:06 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1355 Lines: 29 From: Mel Gorman Date: Thu, 17 May 2012 15:50:26 +0100 > The skb->pfmemalloc flag gets set to true iff during the slab > allocation of data in __alloc_skb that the the PFMEMALLOC reserves > were used. If page splitting is used, it is possible that pages will > be allocated from the PFMEMALLOC reserve without propagating this > information to the skb. This patch propagates page->pfmemalloc from > pages allocated for fragments to the skb. > > It works by reintroducing and expanding the skb_alloc_page() API > to take an skb. If the page was allocated from pfmemalloc reserves, > it is automatically copied. If the driver allocates the page before > the skb, it should call skb_propagate_pfmemalloc() after the skb is > allocated to ensure the flag is copied properly. > > Failure to do so is not critical. The resulting driver may perform > slower if it is used for swap-over-NBD or swap-over-NFS but it should > not result in failure. > > [davem@davemloft.net: API rename and consistency] > Signed-off-by: Mel Gorman Acked-by: David S. Miller -- 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/