From owner-dev-commits-src-all@freebsd.org Wed Jan 6 07:36:11 2021 Return-Path: Delivered-To: dev-commits-src-all@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 C58214C6636; Wed, 6 Jan 2021 07:36:11 +0000 (UTC) (envelope-from git@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 4D9h4W3W5gz4qHK; Wed, 6 Jan 2021 07:36:11 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 3FAF21AD5A; Wed, 6 Jan 2021 07:36:11 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 1067aBET077327; Wed, 6 Jan 2021 07:36:11 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 1067aB81077326; Wed, 6 Jan 2021 07:36:11 GMT (envelope-from git) Date: Wed, 6 Jan 2021 07:36:11 GMT Message-Id: <202101060736.1067aB81077326@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mateusz Guzik Subject: git: deabdc686874 - main - cache: stop pre-checking seqc when starting the lookup MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mjg X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: deabdc686874411bd32775c3bdd04c04d9eff3e5 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Jan 2021 07:36:12 -0000 The branch main has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=deabdc686874411bd32775c3bdd04c04d9eff3e5 commit deabdc686874411bd32775c3bdd04c04d9eff3e5 Author: Mateusz Guzik AuthorDate: 2021-01-06 06:12:58 +0000 Commit: Mateusz Guzik CommitDate: 2021-01-06 07:28:07 +0000 cache: stop pre-checking seqc when starting the lookup Tested by: pho --- sys/kern/vfs_cache.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 710c499d6bb5..138a55f94dbd 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -5032,7 +5032,7 @@ cache_fplookup_skip_slashes(struct cache_fpl *fpl) ndp->ni_next = cnp->cn_nameptr; /* - * Retry the lookup, similar to dot lookups. + * See cache_fplookup_dot. */ fpl->tvp = fpl->dvp; fpl->tvp_seqc = fpl->dvp_seqc; @@ -5139,11 +5139,14 @@ cache_fplookup_impl(struct vnode *dvp, struct cache_fpl *fpl) cache_fpl_checkpoint(fpl, &fpl->snd); + /* + * The vnode is hand is almost always stable, skip checking for it. + * Worst case this postpones the check towards the end of the iteration + * of the main loop. + */ fpl->dvp = dvp; - fpl->dvp_seqc = vn_seqc_read_any(fpl->dvp); - if (seqc_in_modify(fpl->dvp_seqc)) { - return (cache_fpl_aborted(fpl)); - } + fpl->dvp_seqc = vn_seqc_read_notmodify(fpl->dvp); + mp = atomic_load_ptr(&dvp->v_mount); if (__predict_false(mp == NULL || !cache_fplookup_mp_supported(mp))) { return (cache_fpl_aborted(fpl));