Return-path: Received: from py-out-1112.google.com ([64.233.166.179]:60028 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751539AbYFLQfm (ORCPT ); Thu, 12 Jun 2008 12:35:42 -0400 Received: by py-out-1112.google.com with SMTP id p76so1684703pyb.10 for ; Thu, 12 Jun 2008 09:35:40 -0700 (PDT) Message-ID: <1ba2fa240806120935r54a080eci7fa6fafc718eed17@mail.gmail.com> (sfid-20080612_183546_862400_74C1FB2A) Date: Thu, 12 Jun 2008 19:35:39 +0300 From: "Tomas Winkler" To: "Johannes Berg" Subject: Re: Problem: Out of memory after 2days with 2GB RAM Cc: "Rik van Riel" , "Zdenek Kabelac" , "Linux Kernel Mailing List" , yi.zhu@intel.com, reinette.chatre@intel.com, linux-wireless@vger.kernel.org In-Reply-To: <1ba2fa240806120843s268b2ff4mb45a11adf11afc7f@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <20080612093833.0fb9cdd6@bree.surriel.com> <1213278884.3936.15.camel@johannes.berg> <1ba2fa240806120843s268b2ff4mb45a11adf11afc7f@mail.gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Jun 12, 2008 at 6:43 PM, Tomas Winkler wrote: > On Thu, Jun 12, 2008 at 4:54 PM, Johannes Berg > wrote: >> On Thu, 2008-06-12 at 09:38 -0400, Rik van Riel wrote: >>> On Thu, 12 Jun 2008 12:07:34 +0200 >>> "Zdenek Kabelac" wrote: >>> >>> > It looks like while there was a huge amount of buffers and caches - >>> > system was unable to allocate few pages for kmalloc in iwl3945 driver >>> > after resume. >>> >>> It looks like this is because it wants to allocate 2**5 contiguous >>> pages, which is 128kB of contiguous kernel memory. >> >> 64-bit system I assume? >> The allocation should be 256 * 20 * sizeof(struct sk_buff *). > >> Try the patch below. It should improve code generation too. >> >> I discussed this with Tomas previously and he says the hw is capable of >> doing 20 fragments per frame (wonder why, Broadcom can do an unlimited >> number...) but he complained about the networking stack not being able >> to. > > This is scatter gather buffers that can be kicked in one DMA transaction. > > Well, the hardware needs to support IP checksumming for that, hence, >> afaik, only two fragments can ever be used (one for hw header, one for >> frame) > This I still don't understand why but everybody is already tired to > explaining me why.. :) Just need to find time to dig into it. > >> This cuts the allocation to 10%, or (under) a page in all cases. > > Probably. it would be safe to use vmalloc for allocating txb anyway. > I'll give it a try. So vmalloc didn't break anything on the 32bit machine I'm just about to install 64 one so it will take hour or two.. I will issue some official patch after that. > There was already discussion on LKML about memory allocation problems > on X86_64, which might explain this regression. This didn't happen > before. This is the thread title if you are interested. 'x86/kernel/pci_dma.c: gfp |= __GFP_NORETRY' Tomas