From owner-svn-src-all@FreeBSD.ORG Mon Sep 15 17:14:10 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 3AED4158; Mon, 15 Sep 2014 17:14:10 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::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 0CB031CC; Mon, 15 Sep 2014 17:14:10 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id s8FHE9ru098964; Mon, 15 Sep 2014 17:14:09 GMT (envelope-from alc@FreeBSD.org) Received: (from alc@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id s8FHE9Lk098963; Mon, 15 Sep 2014 17:14:09 GMT (envelope-from alc@FreeBSD.org) Message-Id: <201409151714.s8FHE9Lk098963@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: alc set sender to alc@FreeBSD.org using -f From: Alan Cox Date: Mon, 15 Sep 2014 17:14:09 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r271634 - head/sys/vm X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Sep 2014 17:14:10 -0000 Author: alc Date: Mon Sep 15 17:14:09 2014 New Revision: 271634 URL: http://svnweb.freebsd.org/changeset/base/271634 Log: Three improvements to vnode_pager_generic_getpages(): Eliminate an exclusive object lock acquisition and release on the expected execution path. Do page zeroing before the object lock is acquired rather than during the time that the object lock is held. Use vm_pager_free_nonreq() to eliminate duplicated code. Reviewed by: kib MFC after: 6 weeks Sponsored by: EMC / Isilon Storage Division Modified: head/sys/vm/vnode_pager.c Modified: head/sys/vm/vnode_pager.c ============================================================================== --- head/sys/vm/vnode_pager.c Mon Sep 15 16:47:04 2014 (r271633) +++ head/sys/vm/vnode_pager.c Mon Sep 15 17:14:09 2014 (r271634) @@ -772,24 +772,24 @@ vnode_pager_generic_getpages(struct vnod } /* + * Since the caller has busied the requested page, that page's valid + * field will not be changed by other threads. + */ + vm_page_assert_xbusied(m[reqpage]); + + /* * If we have a completely valid page available to us, we can * clean up and return. Otherwise we have to re-read the * media. */ - VM_OBJECT_WLOCK(object); if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { - for (i = 0; i < count; i++) - if (i != reqpage) { - vm_page_lock(m[i]); - vm_page_free(m[i]); - vm_page_unlock(m[i]); - } - VM_OBJECT_WUNLOCK(object); - return VM_PAGER_OK; + vm_pager_free_nonreq(object, m, reqpage, count); + return (VM_PAGER_OK); } else if (reqblock == -1) { pmap_zero_page(m[reqpage]); KASSERT(m[reqpage]->dirty == 0, ("vnode_pager_generic_getpages: page %p is dirty", m)); + VM_OBJECT_WLOCK(object); m[reqpage]->valid = VM_PAGE_BITS_ALL; for (i = 0; i < count; i++) if (i != reqpage) { @@ -799,9 +799,11 @@ vnode_pager_generic_getpages(struct vnod } VM_OBJECT_WUNLOCK(object); return (VM_PAGER_OK); + } else if (m[reqpage]->valid != 0) { + VM_OBJECT_WLOCK(object); + m[reqpage]->valid = 0; + VM_OBJECT_WUNLOCK(object); } - m[reqpage]->valid = 0; - VM_OBJECT_WUNLOCK(object); /* * here on direct device I/O