From owner-svn-src-head@freebsd.org Mon Feb 10 18:06:39 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 7663B23FF50; Mon, 10 Feb 2020 18:06:39 +0000 (UTC) (envelope-from jtl@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 48GYkl2bzLz3KDY; Mon, 10 Feb 2020 18:06:39 +0000 (UTC) (envelope-from jtl@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 54A8822FCB; Mon, 10 Feb 2020 18:06:39 +0000 (UTC) (envelope-from jtl@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 01AI6dw3090912; Mon, 10 Feb 2020 18:06:39 GMT (envelope-from jtl@FreeBSD.org) Received: (from jtl@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 01AI6dru090911; Mon, 10 Feb 2020 18:06:39 GMT (envelope-from jtl@FreeBSD.org) Message-Id: <202002101806.01AI6dru090911@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jtl set sender to jtl@FreeBSD.org using -f From: "Jonathan T. Looney" Date: Mon, 10 Feb 2020 18:06:39 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r357742 - head/sys/vm X-SVN-Group: head X-SVN-Commit-Author: jtl X-SVN-Commit-Paths: head/sys/vm X-SVN-Commit-Revision: 357742 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Feb 2020 18:06:39 -0000 Author: jtl Date: Mon Feb 10 18:06:38 2020 New Revision: 357742 URL: https://svnweb.freebsd.org/changeset/base/357742 Log: Modify the vm.panic_on_oom sysctl to take a count of events. Currently, the vm.panic_on_oom sysctl is a boolean which controls the behavior of the VM system when it encounters an out-of-memory situation. If set to 0, the VM system kills the largest process. If set to any other value, the VM system will initiate a panic. This change makes the sysctl a count of events. If set to 0, the VM system kills the largest process. If set to any other value, the VM system will kill the largest process until it has seen the specified number of out-of-memory events. Once it reaches the specified number of events, it will initiate a panic. This change is helpful in capturing cores when the system is in a perpetual cycle of out-of-memory events (as opposed to just hitting one or two sporadic out-of-memory events). Reviewed by: kib MFC after: 2 weeks Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D23601 Modified: head/sys/vm/vm_pageout.c Modified: head/sys/vm/vm_pageout.c ============================================================================== --- head/sys/vm/vm_pageout.c Mon Feb 10 17:17:08 2020 (r357741) +++ head/sys/vm/vm_pageout.c Mon Feb 10 18:06:38 2020 (r357742) @@ -158,7 +158,7 @@ static int vm_panic_on_oom = 0; SYSCTL_INT(_vm, OID_AUTO, panic_on_oom, CTLFLAG_RWTUN, &vm_panic_on_oom, 0, - "panic on out of memory instead of killing the largest process"); + "Panic on the given number of out-of-memory errors instead of killing the largest process"); SYSCTL_INT(_vm, OID_AUTO, pageout_update_period, CTLFLAG_RWTUN, &vm_pageout_update_period, 0, @@ -1933,7 +1933,7 @@ vm_pageout_oom(int shortage) } sx_sunlock(&allproc_lock); if (bigproc != NULL) { - if (vm_panic_on_oom != 0) + if (vm_panic_on_oom != 0 && --vm_panic_on_oom == 0) panic("out of swap space"); PROC_LOCK(bigproc); killproc(bigproc, "out of swap space");