From owner-svn-src-head@FreeBSD.ORG Sun May 2 17:33:47 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0525D106566B; Sun, 2 May 2010 17:33:47 +0000 (UTC) (envelope-from alc@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [69.147.83.44]) by mx1.freebsd.org (Postfix) with ESMTP id E92E18FC22; Sun, 2 May 2010 17:33:46 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id o42HXkex026825; Sun, 2 May 2010 17:33:46 GMT (envelope-from alc@svn.freebsd.org) Received: (from alc@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id o42HXkpp026820; Sun, 2 May 2010 17:33:46 GMT (envelope-from alc@svn.freebsd.org) Message-Id: <201005021733.o42HXkpp026820@svn.freebsd.org> From: Alan Cox Date: Sun, 2 May 2010 17:33:46 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r207530 - in head/sys: fs/tmpfs kern vm X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 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: Sun, 02 May 2010 17:33:47 -0000 Author: alc Date: Sun May 2 17:33:46 2010 New Revision: 207530 URL: http://svn.freebsd.org/changeset/base/207530 Log: It makes no sense for vm_page_sleep_if_busy()'s helper, vm_page_sleep(), to unconditionally set PG_REFERENCED on a page before sleeping. In many cases, it's perfectly ok for the page to disappear, i.e., be reclaimed by the page daemon, before the caller to vm_page_sleep() is reawakened. Instead, we now explicitly set PG_REFERENCED in those cases where having the page persist until the caller is awakened is clearly desirable. Note, however, that setting PG_REFERENCED on the page is still only a hint, and not a guarantee that the page should persist. Modified: head/sys/fs/tmpfs/tmpfs_vnops.c head/sys/kern/vfs_bio.c head/sys/vm/vm_fault.c head/sys/vm/vm_page.c Modified: head/sys/fs/tmpfs/tmpfs_vnops.c ============================================================================== --- head/sys/fs/tmpfs/tmpfs_vnops.c Sun May 2 16:55:13 2010 (r207529) +++ head/sys/fs/tmpfs/tmpfs_vnops.c Sun May 2 17:33:46 2010 (r207530) @@ -516,8 +516,16 @@ tmpfs_mappedread(vm_object_t vobj, vm_ob lookupvpg: if (((m = vm_page_lookup(vobj, idx)) != NULL) && vm_page_is_valid(m, offset, tlen)) { - if (vm_page_sleep_if_busy(m, FALSE, "tmfsmr")) + if ((m->oflags & VPO_BUSY) != 0) { + /* + * Reference the page before unlocking and sleeping so + * that the page daemon is less likely to reclaim it. + */ + vm_page_lock_queues(); + vm_page_flag_set(m, PG_REFERENCED); + vm_page_sleep(m, "tmfsmr"); goto lookupvpg; + } vm_page_busy(m); VM_OBJECT_UNLOCK(vobj); error = uiomove_fromphys(&m, offset, tlen, uio); @@ -526,8 +534,16 @@ lookupvpg: VM_OBJECT_UNLOCK(vobj); return (error); } else if (m != NULL && uio->uio_segflg == UIO_NOCOPY) { - if (vm_page_sleep_if_busy(m, FALSE, "tmfsmr")) + if ((m->oflags & VPO_BUSY) != 0) { + /* + * Reference the page before unlocking and sleeping so + * that the page daemon is less likely to reclaim it. + */ + vm_page_lock_queues(); + vm_page_flag_set(m, PG_REFERENCED); + vm_page_sleep(m, "tmfsmr"); goto lookupvpg; + } vm_page_busy(m); VM_OBJECT_UNLOCK(vobj); sched_pin(); @@ -627,8 +643,16 @@ tmpfs_mappedwrite(vm_object_t vobj, vm_o lookupvpg: if (((vpg = vm_page_lookup(vobj, idx)) != NULL) && vm_page_is_valid(vpg, offset, tlen)) { - if (vm_page_sleep_if_busy(vpg, FALSE, "tmfsmw")) + if ((vpg->oflags & VPO_BUSY) != 0) { + /* + * Reference the page before unlocking and sleeping so + * that the page daemon is less likely to reclaim it. + */ + vm_page_lock_queues(); + vm_page_flag_set(vpg, PG_REFERENCED); + vm_page_sleep(vpg, "tmfsmw"); goto lookupvpg; + } vm_page_busy(vpg); vm_page_lock_queues(); vm_page_undirty(vpg); Modified: head/sys/kern/vfs_bio.c ============================================================================== --- head/sys/kern/vfs_bio.c Sun May 2 16:55:13 2010 (r207529) +++ head/sys/kern/vfs_bio.c Sun May 2 17:33:46 2010 (r207530) @@ -3024,8 +3024,17 @@ allocbuf(struct buf *bp, int size) * vm_fault->getpages->cluster_read->allocbuf * */ - if (vm_page_sleep_if_busy(m, FALSE, "pgtblk")) + if ((m->oflags & VPO_BUSY) != 0) { + /* + * Reference the page before unlocking + * and sleeping so that the page daemon + * is less likely to reclaim it. + */ + vm_page_lock_queues(); + vm_page_flag_set(m, PG_REFERENCED); + vm_page_sleep(m, "pgtblk"); continue; + } /* * We have a good page. Modified: head/sys/vm/vm_fault.c ============================================================================== --- head/sys/vm/vm_fault.c Sun May 2 16:55:13 2010 (r207529) +++ head/sys/vm/vm_fault.c Sun May 2 17:33:46 2010 (r207530) @@ -338,6 +338,12 @@ RetryFault:; * to pmap it. */ if ((fs.m->oflags & VPO_BUSY) || fs.m->busy) { + /* + * Reference the page before unlocking and + * sleeping so that the page daemon is less + * likely to reclaim it. + */ + vm_page_flag_set(fs.m, PG_REFERENCED); vm_page_unlock_queues(); vm_page_unlock(fs.m); VM_OBJECT_UNLOCK(fs.object); Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Sun May 2 16:55:13 2010 (r207529) +++ head/sys/vm/vm_page.c Sun May 2 17:33:46 2010 (r207530) @@ -599,7 +599,7 @@ vm_page_free_zero(vm_page_t m) /* * vm_page_sleep: * - * Sleep and release the page queues lock. + * Sleep and release the page and page queues locks. * * The object containing the given page must be locked. */ @@ -608,13 +608,10 @@ vm_page_sleep(vm_page_t m, const char *m { VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); - if (!mtx_owned(vm_page_lockptr(m))) - vm_page_lock(m); - if (!mtx_owned(&vm_page_queue_mtx)) - vm_page_lock_queues(); - vm_page_flag_set(m, PG_REFERENCED); - vm_page_unlock_queues(); - vm_page_unlock(m); + if (mtx_owned(&vm_page_queue_mtx)) + vm_page_unlock_queues(); + if (mtx_owned(vm_page_lockptr(m))) + vm_page_unlock(m); /* * It's possible that while we sleep, the page will get @@ -1896,7 +1893,17 @@ vm_page_grab(vm_object_t object, vm_pind VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); retrylookup: if ((m = vm_page_lookup(object, pindex)) != NULL) { - if (vm_page_sleep_if_busy(m, TRUE, "pgrbwt")) { + if ((m->oflags & VPO_BUSY) != 0 || m->busy != 0) { + if ((allocflags & VM_ALLOC_RETRY) != 0) { + /* + * Reference the page before unlocking and + * sleeping so that the page daemon is less + * likely to reclaim it. + */ + vm_page_lock_queues(); + vm_page_flag_set(m, PG_REFERENCED); + } + vm_page_sleep(m, "pgrbwt"); if ((allocflags & VM_ALLOC_RETRY) == 0) return (NULL); goto retrylookup;