From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wr-out-0506.google.com with SMTP id 60so2156559wri.8 for ; Tue, 19 Feb 2008 06:05:00 -0800 (PST) Message-ID: <4cefeab80802190604g1c9fea72ge1052cb3bd597e0a@mail.gmail.com> Date: Tue, 19 Feb 2008 19:34:59 +0530 From: "Nitin Gupta" Subject: Re: [linux-mm-cc] Announce: ccache release 0.1 In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4cefeab80802181339ia9609d3oeb238a9f549fc6e5@mail.gmail.com> <4cefeab80802190406w5dfcb257p1abff260c63522bc@mail.gmail.com> Sender: owner-linux-mm@kvack.org Return-Path: To: John McCabe-Dansted Cc: linux-mm-cc@laptop.org, linux-mm@kvack.org, linuxcompressed-devel@lists.sourceforge.net List-ID: On Feb 19, 2008 6:37 PM, John McCabe-Dansted wrote: > On Feb 19, 2008 9:06 PM, Nitin Gupta wrote: > > On Feb 19, 2008 4:03 PM, John McCabe-Dansted wrote: > > > On Feb 19, 2008 6:39 AM, Nitin Gupta wrote: > > > > Some performance numbers for allocator and de/compressor can be found > > > > on project home. Currently it is tested on Linux kernel 2.6.23.x and > > > > 2.6.25-rc2 (x86 only). Please mail me/mailing-list any > > > > issues/suggestions you have. > > > > > > It caused Gutsy (2.6.22-14-generic) to crash when I did a swap off of > > > my hdd swap. I have a GB of ram, so I would have been fine without > > > ccache. > > > > These days "desktops with small memory" probably means virtual > > machines with, say, <512M RAM :-) > > The Hardy liveCD is really snappy with a 192MB VM and and a 128MB > ccache swap. :) > Good to know :) > > > I had swapped on a 400MB ccache swap. > > > > > > > I need /var/log/messages (or whatever file kernel logs to in Gutsy) to > > debug this. > > Please send it to me offline if its too big. > > This seems to be the bit you want: > Unfortunately none of these messages suggest why crash happened. If you can send entire log, that will probably be more useful. > ubuntu-xp syslogd 1.4.1#21ubuntu3: restart. > Feb 19 08:07:31 ubuntu-xp -- MARK -- > ... > Feb 19 18:47:31 ubuntu-xp -- MARK -- > Feb 19 18:59:51 ubuntu-xp kernel: [377208.185464] ccache: Unknown > symbol lzo1x_decompress_safe All these 'Unknown symbol' messages are because you tried loading ccache.ko module before tlsf.ko and lzo*.ko modules. > > > > BTW, why is the default 10% of mem? > > > > I have no great justification for "10%". > > Perhaps 100% (or maybe 50%) would be a more sensible default? For me > 66% makes a huge difference to the Hardy liveCD performance. 10% makes > a difference but 50%+ goes from "ls /" taking 10s to snappy > performance even on large applications like Firefox. > I think this depends a lot on kind of workload and system. For e.g: - On desktops, retaining too many anonymous pages at cost of continuously losing page-cache (filesystem-backed) pages can hurt performance for workload that repeatedly access same file(s). - On embedded systems, too much de/compression will drain all battery. and so on... Also, I don't know which of these use cases is more "common". - Nitin -- 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