Date: Mon, 23 Apr 2018 07:54:02 +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: r332881 - head/sys/kern Message-ID: <201804230754.w3N7s2o3026836@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: mjg Date: Mon Apr 23 07:54:02 2018 New Revision: 332881 URL: https://svnweb.freebsd.org/changeset/base/332881 Log: lockf: skip locking the graph if not necessary (common case) Tested by: pho Modified: head/sys/kern/kern_lockf.c Modified: head/sys/kern/kern_lockf.c ============================================================================== --- head/sys/kern/kern_lockf.c Mon Apr 23 07:52:56 2018 (r332880) +++ head/sys/kern/kern_lockf.c Mon Apr 23 07:54:02 2018 (r332881) @@ -1053,6 +1053,12 @@ lf_add_incoming(struct lockf *state, struct lockf_entr struct lockf_entry *overlap; int error; + sx_assert(&state->ls_lock, SX_XLOCKED); + if (LIST_EMPTY(&state->ls_pending)) + return (0); + + error = 0; + sx_xlock(&lf_owner_graph_lock); LIST_FOREACH(overlap, &state->ls_pending, lf_link) { if (!lf_blocks(lock, overlap)) continue; @@ -1070,10 +1076,11 @@ lf_add_incoming(struct lockf *state, struct lockf_entr */ if (error) { lf_remove_incoming(lock); - return (error); + break; } } - return (0); + sx_xunlock(&lf_owner_graph_lock); + return (error); } /* @@ -1509,9 +1516,7 @@ lf_setlock(struct lockf *state, struct lockf_entry *lo * edges from any currently pending lock that the new lock * would block. */ - sx_xlock(&lf_owner_graph_lock); error = lf_add_incoming(state, lock); - sx_xunlock(&lf_owner_graph_lock); if (error) { #ifdef LOCKF_DEBUG if (lockf_debug & 1) @@ -1840,9 +1845,7 @@ lf_split(struct lockf *state, struct lockf_entry *lock splitlock->lf_start = lock2->lf_end + 1; LIST_INIT(&splitlock->lf_outedges); LIST_INIT(&splitlock->lf_inedges); - sx_xlock(&lf_owner_graph_lock); lf_add_incoming(state, splitlock); - sx_xunlock(&lf_owner_graph_lock); lf_set_end(state, lock1, lock2->lf_start - 1, granted);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201804230754.w3N7s2o3026836>