From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from haymarket.ed.ac.uk (haymarket.ed.ac.uk [129.215.128.53]) by kvack.org (8.8.7/8.8.7) with ESMTP id NAA07541 for ; Wed, 8 Jul 1998 13:13:47 -0400 Date: Wed, 8 Jul 1998 14:45:49 +0100 Message-Id: <199807081345.OAA01509@dax.dcs.ed.ac.uk> From: "Stephen C. Tweedie" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Re: cp file /dev/zero <-> cache [was Re: increasing page size] In-Reply-To: References: <199807071201.NAA00934@dax.dcs.ed.ac.uk> Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: "Stephen C. Tweedie" , Andrea Arcangeli , Linux MM , Linux Kernel List-ID: Hi, On Tue, 7 Jul 1998 17:54:46 +0200 (CEST), Rik van Riel said: > There's a good compromize between balancing per-page > and per-process. We can simply declare the last X > (say 8) pages of a process holy unless that process > has slept for more than Y (say 5) seconds. Yep --- this is per-process RSS management, and there is a _lot_ we can do once we start following this route. I've been talking with some folk about it already, and this is something we definitely want to look into for 2.3. For example, we can do both RSS limits (upper limits to RSS) plus RSS quotas (a guaranteed lower limit which we allocate to the process). Consider a machine where we have some very large processes thrashing away; placing an RSS limit on those excessive processes will prevent them from hogging all of physical memory, and giving interactive processes a small guaranteed RSS quota will ensure that those processes are allowed to make at least some progress even under severe VM load. The hard part is the self-tuning --- making sure that we don't give a resident quota to idle processes, so that they can be fully swapped out, and making sure that we don't overly trim back large processes for which there is actually sufficient physical memory. However, the principle of RSS management is a powerful one and we should most certainly be doing this for 2.3. --Stephen -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org