From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ed Tomlinson Subject: Re: [PATCH] 0/2 swap token tuning Date: Mon, 27 Jun 2005 19:46:32 -0400 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200506271946.33083.tomlins@cam.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik Van Riel Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Song Jiang List-ID: On Sunday 26 June 2005 18:34, Rik Van Riel wrote: > A while ago the swap token (aka token based thrashing control) > mechanism was introduced into Linux. This code improves performance > under heavy VM loads, but can reduce performance under very light > VM loads. > > The cause turns out to be me overlooking something in the original > token based thrashing control paper: the swap token is only supposed > to be enforced while the task holding the swap token is paging data > in, not while the task is running (and referencing its working set). > > The temporary solution in Linux was to disable the swap token code > and have users turn it on again via /proc. The following patch > instead approximates the "only enforce the swap token if the task > holding it is swapping something in" idea. This should make sure > the swap token is effectively disabled when the VM load is low. > > I have not benchmarked these patches yet; instead, I'm posting > them before the weekend is over, hoping to catch a bit of test > time from others while my own tests are being run ;) Rik, What are the suggested values to put into /proc/sys/vm/swap_token_timeout ? The docs are not at all clear about this (proc/filesystems.txt). TIA, Ed Tomlinson -- 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