From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 16 Jun 2005 17:51:30 -0700 From: Andrew Morton Subject: Re: 2.6.12-rc6-mm1 & 2K lun testing Message-Id: <20050616175130.22572451.akpm@osdl.org> In-Reply-To: <1118965381.4301.488.camel@dyn9047017072.beaverton.ibm.com> References: <1118856977.4301.406.camel@dyn9047017072.beaverton.ibm.com> <20050616002451.01f7e9ed.akpm@osdl.org> <1118951458.4301.478.camel@dyn9047017072.beaverton.ibm.com> <20050616133730.1924fca3.akpm@osdl.org> <1118965381.4301.488.camel@dyn9047017072.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Badari Pulavarty Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Badari Pulavarty wrote: > > > Try this: > > > > diff -puN mm/page-writeback.c~a mm/page-writeback.c > > --- 25/mm/page-writeback.c~a Thu Jun 16 13:36:29 2005 > > +++ 25-akpm/mm/page-writeback.c Thu Jun 16 13:36:54 2005 > > @@ -501,6 +501,8 @@ void laptop_sync_completion(void) > > > > static void set_ratelimit(void) > > { > > + ratelimit_pages = 32; > > + return; > > ratelimit_pages = total_pages / (num_online_cpus() * 32); > > if (ratelimit_pages < 16) > > ratelimit_pages = 16; > > _ > > > > Wow !! Reducing the dirty ratios and the above patch did the trick. > Instead of 100% sys CPU, now I have only 50% in sys. It shouldn't be necessary to do both. Either the patch or the tuning should fix it. Please confirm. Also please determine whether the deep CFQ queue depth is a problem when the VFS tuning/patching is in place. IOW: let's work out which of these three areas needs to be addressed. -- 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: aart@kvack.org