From owner-svn-src-head@freebsd.org Sat Oct 21 17:28:14 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 144B9E34526; Sat, 21 Oct 2017 17:28:14 +0000 (UTC) (envelope-from kib@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 mx1.freebsd.org (Postfix) with ESMTPS id CAC5864661; Sat, 21 Oct 2017 17:28:13 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v9LHSCqc065497; Sat, 21 Oct 2017 17:28:12 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v9LHSCb4065496; Sat, 21 Oct 2017 17:28:12 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201710211728.v9LHSCb4065496@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Sat, 21 Oct 2017 17:28:12 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r324824 - head/sys/vm X-SVN-Group: head X-SVN-Commit-Author: kib X-SVN-Commit-Paths: head/sys/vm X-SVN-Commit-Revision: 324824 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: 2.1.23 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: Sat, 21 Oct 2017 17:28:14 -0000 Author: kib Date: Sat Oct 21 17:28:12 2017 New Revision: 324824 URL: https://svnweb.freebsd.org/changeset/base/324824 Log: Check that the page which is freed as zeroed, indeed has all-zero content. This catches some rare mysterious failures at the source. The check is only performed on architectures which implement direct map, and only enabled with option DIAGNOSTIC, similar to other costly consistency checks. Reviewed by: alc, markj Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Modified: head/sys/vm/vm_page.c Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Sat Oct 21 16:55:52 2017 (r324823) +++ head/sys/vm/vm_page.c Sat Oct 21 17:28:12 2017 (r324824) @@ -2780,6 +2780,16 @@ bool vm_page_free_prep(vm_page_t m, bool pagequeue_locked) { +#if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) + if ((m->flags & PG_ZERO) != 0) { + uint64_t *p; + int i; + p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); + for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) + KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", + m, i, (uintmax_t)*p)); + } +#endif if ((m->oflags & VPO_UNMANAGED) == 0) { vm_page_lock_assert(m, MA_OWNED); KASSERT(!pmap_page_is_mapped(m),