From owner-svn-src-head@freebsd.org Mon Aug 10 10:36:45 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 06A4237DEF0; Mon, 10 Aug 2020 10:36:45 +0000 (UTC) (envelope-from mjg@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) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 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 4BQC7c6Mc7z46wP; Mon, 10 Aug 2020 10:36:44 +0000 (UTC) (envelope-from mjg@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 BDF6A8D8C; Mon, 10 Aug 2020 10:36:44 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 07AAaiXf096624; Mon, 10 Aug 2020 10:36:44 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 07AAaiBA096621; Mon, 10 Aug 2020 10:36:44 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <202008101036.07AAaiBA096621@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Mon, 10 Aug 2020 10:36:44 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r364069 - head/sys/fs/devfs X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: head/sys/fs/devfs X-SVN-Commit-Revision: 364069 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: 2.1.33 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 Aug 2020 10:36:45 -0000 Author: mjg Date: Mon Aug 10 10:36:43 2020 New Revision: 364069 URL: https://svnweb.freebsd.org/changeset/base/364069 Log: devfs: save on spurious relocking for devfs_populate Tested by: pho Modified: head/sys/fs/devfs/devfs.h head/sys/fs/devfs/devfs_devs.c head/sys/fs/devfs/devfs_vnops.c Modified: head/sys/fs/devfs/devfs.h ============================================================================== --- head/sys/fs/devfs/devfs.h Mon Aug 10 10:36:10 2020 (r364068) +++ head/sys/fs/devfs/devfs.h Mon Aug 10 10:36:43 2020 (r364069) @@ -192,6 +192,7 @@ char *devfs_fqpn(char *, struct devfs_mount *, struct struct componentname *); void devfs_delete(struct devfs_mount *, struct devfs_dirent *, int); void devfs_dirent_free(struct devfs_dirent *); +bool devfs_populate_needed(struct devfs_mount *dm); void devfs_populate(struct devfs_mount *); void devfs_cleanup(struct devfs_mount *); void devfs_unmount_final(struct devfs_mount *); Modified: head/sys/fs/devfs/devfs_devs.c ============================================================================== --- head/sys/fs/devfs/devfs_devs.c Mon Aug 10 10:36:10 2020 (r364068) +++ head/sys/fs/devfs/devfs_devs.c Mon Aug 10 10:36:43 2020 (r364069) @@ -659,6 +659,13 @@ devfs_populate_loop(struct devfs_mount *dm, int cleanu return (0); } +bool +devfs_populate_needed(struct devfs_mount *dm) +{ + + return (dm->dm_generation != devfs_generation); +} + /* * The caller needs to hold the dm for the duration of the call. */ @@ -668,9 +675,9 @@ devfs_populate(struct devfs_mount *dm) unsigned gen; sx_assert(&dm->dm_lock, SX_XLOCKED); - gen = devfs_generation; - if (dm->dm_generation == gen) + if (!devfs_populate_needed(dm)) return; + gen = devfs_generation; while (devfs_populate_loop(dm, 0)) continue; dm->dm_generation = gen; Modified: head/sys/fs/devfs/devfs_vnops.c ============================================================================== --- head/sys/fs/devfs/devfs_vnops.c Mon Aug 10 10:36:10 2020 (r364068) +++ head/sys/fs/devfs/devfs_vnops.c Mon Aug 10 10:36:43 2020 (r364069) @@ -235,6 +235,11 @@ devfs_populate_vp(struct vnode *vp) ASSERT_VOP_LOCKED(vp, "devfs_populate_vp"); dmp = VFSTODEVFS(vp->v_mount); + if (!devfs_populate_needed(dmp)) { + sx_xlock(&dmp->dm_lock); + goto out_nopopulate; + } + locked = VOP_ISLOCKED(vp); sx_xlock(&dmp->dm_lock); @@ -252,6 +257,7 @@ devfs_populate_vp(struct vnode *vp) devfs_unmount_final(dmp); return (ERESTART); } +out_nopopulate: if (VN_IS_DOOMED(vp)) { sx_xunlock(&dmp->dm_lock); return (ERESTART);