From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <39E29B4D.C365FD12@kalifornia.com> Date: Mon, 09 Oct 2000 21:30:05 -0700 From: David Ford Reply-To: david+validemail@kalifornia.com MIME-Version: 1.0 Subject: Re: [PATCH] VM fix for 2.4.0-test9 & OOM handler References: <200010100422.e9A4Mg722840@webber.adilger.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andreas Dilger Cc: Rik van Riel , mingo@elte.hu, Andrea Arcangeli , Byron Stanoszek , Linus Torvalds , MM mailing list , linux-kernel@vger.kernel.org, jg@pa.dec.com, Gerrit.Huizenga@us.ibm.com List-ID: Andreas Dilger wrote: > Albert D. Cahalan wrote: > > X, and any other big friendly processes, could participate in > > memory balancing operations. X could be made to clean out a > > Gerrit Huizenga wrote: > > Anyway, there is/was an API in PTX to say (either from in-kernel or through > > some user machinations) "I Am a System Process". Turns on a bit in the > > On AIX there is a signal called SIGDANGER, which is basically what you > are looking for. By default it is ignored, but for processes that care > (e.g. init, X, whatever) they can register a SIGDANGER handler. At an > "urgent" (as oposed to "critical") OOM situation, all processes get a > SIGDANGER sent to them. Most will ignore it, but ones with handlers > can free caches, try to do a clean shutdown, whatever. Any process with > a SIGDANGER handler get a reduction of "badness" (as the OOM killer calls > it) when looking for processes to kill. > > Having a SIGDANGER handler is good for 2 reasons: > 1) Lets processes know when memory is short so they can free needless cache. > 2) Mark process with a SIGDANGER handler as "more important" than those > without. Most people won't care about this, but init, and X, and > long-running simulations might. Is there any reason why we can't do something like this for 2.5? -d -- "There is a natural aristocracy among men. The grounds of this are virtue and talents", Thomas Jefferson [1742-1826], 3rd US President -- 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.eu.org/Linux-MM/