From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: Re: bcache and memory at boot. Bug? Date: Mon, 10 Feb 2014 14:46:48 -0800 Message-ID: <20140210224648.GC2362@kmo> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pd0-f179.google.com ([209.85.192.179]:43773 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752179AbaBJWqv (ORCPT ); Mon, 10 Feb 2014 17:46:51 -0500 Received: by mail-pd0-f179.google.com with SMTP id fp1so6287845pdb.24 for ; Mon, 10 Feb 2014 14:46:51 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Josep Lladonosa Cc: Gabriel de Perthuis , "linux-bcache@vger.kernel.org" On Mon, Feb 10, 2014 at 02:15:14PM +0100, Josep Lladonosa wrote: > On 10 February 2014 12:40, Gabriel de Perthuis wrote: > >> Hello, > >> > >> I am using bcache in my laptop (RAM 32 GiB). I have been using it > >> perfectly for a month. ext4 + bcache. > >> > >> Yesterday, system did not want do to a normal startup. Messages where > >> from udev out of memory (and udevadm killed?) and system was not > >> mounting / (/dev/bcache0). > >> > >> [ 6.823222] bcache-register invoked oom-killer: gfp_mask=0x82d2, > >> order=0, oom_score_adj=0 > > > > Build your kernel with CONFIG_COMPACTION. I've added it to the FAQ: > > http://bcache.evilpiepirate.org/~kent/bcache/FAQ/ > > > Hello Gabriel, > > Thanks for your reply. > > My .config file has already: > ... > CONFIG_COMPACTION=y I looked at the allocations done in bcache_device_init(), those aren't high order page allocations (they're vmalloc allocations) so compaction won't help here. > ... > > I have been digging around to find information and sometimes bugs come > related to unsigned variables and their operations when storing large > numbers (reserved memory?). Kernel is 64 bits. Memory is 32 GiB. > Perhaps it could happen that the allocated memory is not totally > freed. > > When kernel has been able to boot with 32 GiB (having bcache0 messed > up and bcache1 mountable), it seems that bcache has more than 16 GiB > allocated and kept. Woah, really? If so that's bad - I don't see how that follows (or am I misreading) from your numbers, can you show a before and after when you bring bcache up? > > -Free memory with kernel 3.11.0-rc7 with 32GiB and bcache0 (halved?) > and bcache1 (mounted) > > $ head -2 /proc/meminfo > MemTotal: 32913872 kB > MemFree: 12376640 kB > > > - Free memory with kernel 3.12.9 with mem=16G and bcache0 (mounted) > > $ head -2 /proc/meminfo > MemTotal: 15602144 kB > MemFree: 14005372 kB > > > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- > -- > Salutacions...Josep > -- > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html