From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 21 Sep 2001 11:27:23 -0400 Subject: Re: broken VM in 2.4.10-pre9 Message-ID: <20010921112722.A3646@cs.cmu.edu> References: <20010921080549Z16344-2758+350@humbolt.nl.linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010921080549Z16344-2758+350@humbolt.nl.linux.org> From: Jan Harkes Sender: owner-linux-mm@kvack.org Return-Path: To: Daniel Phillips Cc: Rik van Riel , Alan Cox , "Eric W. Biederman" , Rob Fuller , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, Sep 21, 2001 at 10:13:11AM +0200, Daniel Phillips wrote: > - small inactive list really means large active list (and vice versa) > - aging increments need to depend on the size of the active list > - "exponential" aging may be completely bogus I don't think so, whenever there is sufficient memory pressure, the scan of the active list is not only done by kswapd, but also by the page allocations. This does have the nice effect that with a large active list on a system that has a working set that fits in memory, pages basically always age up, and we get an automatic used-once/drop-behind behaviour for streaming data because the age of these pages is relatively low. As soon as the rate of new allocations increases to the point that kswapd can't keep up, which happens if the number of cached used-once pages is too small, or the working set expands so that it doesn't fit in memory. The memory shortage then causes all pages to agressively get aged down, pushing out the less frequently used pages of the working set. Exponential down aging simply causes us to loop fewer times in do_try_to_free_pages is such situations. Jan -- 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/