From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC][PATCH 0/9] Network receive deadlock prevention for NBD From: Peter Zijlstra 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 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Evgeniy Polyakov Cc: Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Daniel Phillips List-ID: 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, 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