From owner-freebsd-arch Mon Mar 24 18:12:59 2003 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 896A337B401; Mon, 24 Mar 2003 18:12:56 -0800 (PST) Received: from mail01.stbernard.com (mail01.stbernard.com [64.154.93.162]) by mx1.FreeBSD.org (Postfix) with ESMTP id D548543F3F; Mon, 24 Mar 2003 18:12:55 -0800 (PST) (envelope-from wes@softweyr.com) Received: from salty.rapid.stbernard.com ([192.168.4.61]) by mail01.stbernard.com with Microsoft SMTPSVC(5.0.2195.5329); Mon, 24 Mar 2003 18:12:55 -0800 From: Wes Peters Organization: Softweyr.com To: David Schultz Subject: Re: Patch to protect process from pageout killing Date: Mon, 24 Mar 2003 18:12:55 -0800 User-Agent: KMail/1.5 Cc: freebsd-arch@FreeBSD.ORG References: <200303240823.48262.wes@softweyr.com> <20030325012303.GA4406@HAL9000.homeunix.com> In-Reply-To: <20030325012303.GA4406@HAL9000.homeunix.com> X-Habeas-SWE-1: winter into spring X-Habeas-SWE-2: brightly anticipated X-Habeas-SWE-3: like Habeas SWE (tm) X-Habeas-SWE-4: Copyright 2002 Habeas (tm) X-Habeas-SWE-5: Sender Warranted Email (SWE) (tm). The sender of this X-Habeas-SWE-6: email in exchange for a license for this Habeas X-Habeas-SWE-7: warrant mark warrants that this is a Habeas Compliant X-Habeas-SWE-8: Message (HCM) and not spam. Please report use of this X-Habeas-SWE-9: mark in spam to . MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200303241812.55290.wes@softweyr.com> X-OriginalArrivalTime: 25 Mar 2003 02:12:55.0571 (UTC) FILETIME=[0C440E30:01C2F274] X-Spam-Status: No, hits=-25.8 required=5.0 tests=AWL,EMAIL_ATTRIBUTION,IN_REP_TO,QUOTED_EMAIL_TEXT, QUOTE_TWICE_1,RCVD_IN_UNCONFIRMED_DSBL,REFERENCES, REPLY_WITH_QUOTES,USER_AGENT autolearn=ham version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Monday 24 March 2003 17:23, David Schultz wrote: > Thus spake Wes Peters : > > As promised, here's the patch to protect a process from being > > killed when pageout is in memory shortage. This allows a process > > to specify that it is important enough to be skipped when pageout > > is looking for the largest process to kill. > > > > My needs are simple. We make a box that is a web proxy and runs > > from a memory disk, using flash for permanent storage. The flash > > is mounted only when a configuration write is needed, the box runs > > from the memory disk. We've experienced a problem at certain > > customer sites where bind will consume a lot (~30 MB) of ram and > > then pageout will kill the largest process, which is usually either > > named or squid. This pretty much kills the box. We'd much rather > > have pageout kill off some of the squid worker processes, we can > > recover from that. > > Very nice. Inheritance of this attribute seems to be a > contentious issue. Making inheritance tunable might be a good > idea. You wouldn't be able to piggyback on rlimit, though. Actually inheritance was unintentional, I'm waiting for feedback on what I should've done to make it not inherited. Any help you can offer will be appreciated. > There's a significant userland component of this as well, although > that's probably a job for another day. It basically consists of > making it possible to specify that certain standard system daemons > should have this attribute. Yup. > > + (p->p_flag & P_PROTECTED) || > > ((p->p_pid < 48) && (vm_swap_size != 0))) { > > PROC_UNLOCK(p); > > continue; > > The pid < 48 magic can probably go away, while you're at it. I'd be happy to -- that 48 makes me nervous -- if a couple more Really Smart(tm) guys say it's OK. ;^) -- "Where am I, and what am I doing in this handbasket?" Wes Peters wes@softweyr.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message