Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751380AbWHLLlT (ORCPT ); Sat, 12 Aug 2006 07:41:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751437AbWHLLlT (ORCPT ); Sat, 12 Aug 2006 07:41:19 -0400 Received: from amsfep17-int.chello.nl ([213.46.243.15]:41674 "EHLO amsfep19-int.chello.nl") by vger.kernel.org with ESMTP id S1750847AbWHLLlT (ORCPT ); Sat, 12 Aug 2006 07:41:19 -0400 Subject: Re: [RFC][PATCH 0/9] Network receive deadlock prevention for NBD From: Peter Zijlstra To: Evgeniy Polyakov Cc: Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Daniel Phillips In-Reply-To: <20060812104224.GA12353@2ka.mipt.ru> References: <20060808193325.1396.58813.sendpatchset@lappy> <20060809054648.GD17446@2ka.mipt.ru> <1155127040.12225.25.camel@twins> <20060809130752.GA17953@2ka.mipt.ru> <1155130353.12225.53.camel@twins> <44DD4E3A.4040000@redhat.com> <20060812084713.GA29523@2ka.mipt.ru> <1155374390.13508.15.camel@lappy> <20060812093706.GA13554@2ka.mipt.ru> <1155377887.13508.27.camel@lappy> <20060812104224.GA12353@2ka.mipt.ru> Content-Type: text/plain Date: Sat, 12 Aug 2006 13:40:29 +0200 Message-Id: <1155382830.13508.38.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1249 Lines: 26 On Sat, 2006-08-12 at 14:42 +0400, Evgeniy Polyakov wrote: > When network uses the same allocator, it depends on it, and thus it is > possible to have (cut by you) a situation when reserve (which depends on > SLAB and it's OOM too) is not filled or even does not exist. No, the reserve does not depend on SLAB, and I totally short-circuit the SLAB allocator for skbs and related on memory pressure. The memalloc reserve is on the page allocator level and is only accessable for PF_MEMALLOC processes or __GFP_MEMALLOC (new in my patches) allocations. (arguably there could be some more deadlocks wrt. PF_MEMALLOC where the code under PF_MEMALLOC is not properly bounded, those would be bugs and should be fixed if present/found) > If transferred to your implementation, then just steal some pages from > SLAB when new network device is added and use them when OOM happens. > It is much simpler and can help in the most of situations. SLAB reclaim is painfull and has been tried by the time you OOM. - 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/