lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sun, 1 Aug 2010 21:03:01 +0800 From: Wu Fengguang <fengguang.wu@...el.com> To: Andrew Morton <akpm@...ux-foundation.org> Cc: Mel Gorman <mel@....ul.ie>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>, "linux-mm@...ck.org" <linux-mm@...ck.org>, Dave Chinner <david@...morbit.com>, Chris Mason <chris.mason@...cle.com>, Nick Piggin <npiggin@...e.de>, Rik van Riel <riel@...hat.com>, Johannes Weiner <hannes@...xchg.org>, Jens Axboe <axboe@...nel.dk>, Christoph Hellwig <hch@...radead.org>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>, KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>, Andrea Arcangeli <aarcange@...hat.com>, pvz@....pp.se, bgamari@...il.com, larppaxyz@...il.com, seanj@...e.com, kernel-bugs.dev1world@...mgourmet.com, akatopaz@...il.com, frankrq2009@....com, thomas.pi@...or.de, spawels13@...il.com, vshader@...il.com, rockorequin@...mail.com, ylalym@...il.com, theholyettlz@...glemail.com, hassium@...dex.ru Subject: Re: [PATCH 6/6] vmscan: Kick flusher threads to clean pages when reclaim is encountering dirty pages On Sun, Aug 01, 2010 at 07:56:40PM +0800, Wu Fengguang wrote: > > Sigh. We have sooo many problems with writeback and latency. Read > > https://bugzilla.kernel.org/show_bug.cgi?id=12309 and weep. Everyone's > > running away from the issue and here we are adding code to solve some > > alleged stack-overflow problem which seems to be largely a non-problem, > > by making changes which may worsen our real problems. > > I'm sweeping bug 12309. Most people reports some data writes, though > relative few explicitly stated memory pressure is another necessary > condition. #14: Per von Zweigbergk Ubuntu 2.6.27 slowdown when copying 25MB/s USB stick to 10 MB/s SSD. KOSAKI and my patches won't fix 2.6.27, since it only do congestion_wait() and wait_on_page_writeback() for order>3 allocations. There may be more bugs there. #24: Per von Zweigbergk The encryption of the SSD very significantly increases the problem. This is expected. Data encryption roughly doubles page consumption speed (there may be temp buffers allocated/dropped quickly), hence vmscan pressure. #26: Per von Zweigbergk Disabling swap makes the terminal launch much faster while copying; However Firefox and vim hang much more aggressively and frequently during copying. It's interesting to see processes behave differently. Is this reproducible at all? #34: Ben Gamari There is evidence that x86-64 is a factor here. Because x86-64 does order-1 page allocation in fork() and consumes more memory (larger user space code/data)? #36: Lari Temmes Go from usable to totally unusable when switching from a SMP kernel to a UP kernel on a single CPU laptop He should be testing 2.6.28. I'm not aware of known bugs there. #47: xyke Renicing pdflush -10 had some great improvement on basic responsiveness. It sure helps :) Too much (old) messages there. I'm hoping some of the still active bug reporters to test the following patches (they are for the -mmotm tree, need to unindent code for Linus's tree) and see if there are any improvements. http://lkml.org/lkml/2010/8/1/40 http://lkml.org/lkml/2010/8/1/45 Thanks, Fengguang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists