From owner-svn-src-all@freebsd.org Thu Dec 10 22:57:28 2015 Return-Path: Delivered-To: svn-src-all@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 780909D765A; Thu, 10 Dec 2015 22:57:28 +0000 (UTC) (envelope-from cem@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 30C4619E0; Thu, 10 Dec 2015 22:57:28 +0000 (UTC) (envelope-from cem@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id tBAMvRxv083368; Thu, 10 Dec 2015 22:57:27 GMT (envelope-from cem@FreeBSD.org) Received: (from cem@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id tBAMvR8H083367; Thu, 10 Dec 2015 22:57:27 GMT (envelope-from cem@FreeBSD.org) Message-Id: <201512102257.tBAMvR8H083367@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: cem set sender to cem@FreeBSD.org using -f From: "Conrad E. Meyer" Date: Thu, 10 Dec 2015 22:57:27 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r292067 - 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: 2.1.20 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: Thu, 10 Dec 2015 22:57:28 -0000 Author: cem Date: Thu Dec 10 22:57:27 2015 New Revision: 292067 URL: https://svnweb.freebsd.org/changeset/base/292067 Log: vm_page_replace: remove redundant radix lookup Remove redundant lookup of the old page from vm_page_replace. Verification that the old page exists is already done by vm_radix_replace. Submitted by: Ryan Libby Reviewed by: alc, kib Sponsored by: EMC / Isilon Storage Division Follow-up to: https://reviews.freebsd.org/D4326 Differential Revision: https://reviews.freebsd.org/D4471 Modified: head/sys/vm/vm_page.c Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Thu Dec 10 21:46:21 2015 (r292066) +++ head/sys/vm/vm_page.c Thu Dec 10 22:57:27 2015 (r292067) @@ -1324,22 +1324,17 @@ vm_page_prev(vm_page_t m) vm_page_t vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex) { - vm_page_t mold, mpred; + vm_page_t mold; VM_OBJECT_ASSERT_WLOCKED(object); + KASSERT(mnew->object == NULL, + ("vm_page_replace: page already in object")); /* * This function mostly follows vm_page_insert() and * vm_page_remove() without the radix, object count and vnode * dance. Double check such functions for more comments. */ - mpred = vm_radix_lookup(&object->rtree, pindex); - KASSERT(mpred != NULL, - ("vm_page_replace: replacing page not present with pindex")); - mpred = TAILQ_PREV(mpred, respgs, listq); - if (mpred != NULL) - KASSERT(mpred->pindex < pindex, - ("vm_page_insert_after: mpred doesn't precede pindex")); mnew->object = object; mnew->pindex = pindex; @@ -1347,17 +1342,17 @@ vm_page_replace(vm_page_t mnew, vm_objec KASSERT(mold->queue == PQ_NONE, ("vm_page_replace: mold is on a paging queue")); - /* Detach the old page from the resident tailq. */ + /* Keep the resident page list in sorted order. */ + TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq); TAILQ_REMOVE(&object->memq, mold, listq); mold->object = NULL; vm_page_xunbusy(mold); - /* Insert the new page in the resident tailq. */ - if (mpred != NULL) - TAILQ_INSERT_AFTER(&object->memq, mpred, mnew, listq); - else - TAILQ_INSERT_HEAD(&object->memq, mnew, listq); + /* + * The object's resident_page_count does not change because we have + * swapped one page for another, but OBJ_MIGHTBEDIRTY. + */ if (pmap_page_is_write_mapped(mnew)) vm_object_set_writeable_dirty(object); return (mold);