Date: Sat, 1 Aug 2020 06:34:19 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r363755 - head/sys/kern Message-ID: <202008010634.0716YJ3M041756@repo.freebsd.org>
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Author: mjg Date: Sat Aug 1 06:34:18 2020 New Revision: 363755 URL: https://svnweb.freebsd.org/changeset/base/363755 Log: cache: mark climb_mount as __noinline Modified: head/sys/kern/vfs_cache.c Modified: head/sys/kern/vfs_cache.c ============================================================================== --- head/sys/kern/vfs_cache.c Sat Aug 1 06:33:38 2020 (r363754) +++ head/sys/kern/vfs_cache.c Sat Aug 1 06:34:18 2020 (r363755) @@ -3448,7 +3448,7 @@ cache_fplookup_mp_supported(struct mount *mp) * By the end of successful walk we are guaranteed the reached state was * indeed present at least at some point which matches the regular lookup. */ -static int +static int __noinline cache_fplookup_climb_mount(struct cache_fpl *fpl) { struct mount *mp, *prev_mp; @@ -3457,9 +3457,8 @@ cache_fplookup_climb_mount(struct cache_fpl *fpl) vp = fpl->tvp; vp_seqc = fpl->tvp_seqc; - if (vp->v_type != VDIR) - return (0); + VNPASS(vp->v_type == VDIR || vp->v_type == VBAD, vp); mp = atomic_load_ptr(&vp->v_mountedhere); if (mp == NULL) return (0); @@ -3503,6 +3502,26 @@ cache_fplookup_climb_mount(struct cache_fpl *fpl) return (0); } +static bool +cache_fplookup_need_climb_mount(struct cache_fpl *fpl) +{ + struct mount *mp; + struct vnode *vp; + + vp = fpl->tvp; + + /* + * Hack: while this is a union, the pointer tends to be NULL so save on + * a branch. + */ + mp = atomic_load_ptr(&vp->v_mountedhere); + if (mp == NULL) + return (false); + if (vp->v_type == VDIR) + return (true); + return (false); +} + /* * Parse the path. * @@ -3689,9 +3708,11 @@ cache_fplookup_impl(struct vnode *dvp, struct cache_fp VNPASS(!seqc_in_modify(fpl->tvp_seqc), fpl->tvp); - error = cache_fplookup_climb_mount(fpl); - if (__predict_false(error != 0)) { - break; + if (cache_fplookup_need_climb_mount(fpl)) { + error = cache_fplookup_climb_mount(fpl); + if (__predict_false(error != 0)) { + break; + } } VNPASS(!seqc_in_modify(fpl->tvp_seqc), fpl->tvp);
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