From 2ffb755cec6819c178a959148e003b622f407116 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Fri, 11 Apr 2014 19:17:45 +0000 Subject: [PATCH] The tw_pcbrele() function does not need the global timewait lock. Submitted by: Julien Charbon Suggested by: glebius --- sys/netinet/tcp_timewait.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c index b55ea06e3fb1..d99416d77b1a 100644 --- a/sys/netinet/tcp_timewait.c +++ b/sys/netinet/tcp_timewait.c @@ -133,23 +133,18 @@ tw_pcbref(struct tcptw *tw) } /* - * Drop a refcount on an tw elevated using tw_pcbref(). Return - * the tw lock released. + * Drop a refcount on an tw elevated using tw_pcbref(). */ static int tw_pcbrele(struct tcptw *tw) { - TW_WLOCK_ASSERT(V_tw_lock); KASSERT(tw->tw_refcount > 0, ("%s: refcount 0", __func__)); - if (!refcount_release(&tw->tw_refcount)) { - TW_WUNLOCK(V_tw_lock); + if (!refcount_release(&tw->tw_refcount)) return (0); - } uma_zfree(V_tcptw_zone, tw); - TW_WUNLOCK(V_tw_lock); return (1); } @@ -682,13 +677,10 @@ tcp_tw_2msl_stop(struct tcptw *tw, int reuse) TAILQ_REMOVE(&V_twq_2msl, tw, tw_2msl); crfree(tw->tw_cred); tw->tw_cred = NULL; - - if (!reuse) { - tw_pcbrele(tw); - return; - } - TW_WUNLOCK(V_tw_lock); + + if (!reuse) + tw_pcbrele(tw); } struct tcptw * @@ -730,7 +722,6 @@ tcp_tw_2msl_scan(void) /* Close timewait state */ if (INP_INFO_TRY_WLOCK(&V_tcbinfo)) { - TW_WLOCK(V_tw_lock); if (tw_pcbrele(tw)) { INP_INFO_WUNLOCK(&V_tcbinfo); continue; @@ -744,7 +735,6 @@ tcp_tw_2msl_scan(void) INP_INFO_WUNLOCK(&V_tcbinfo); } else { /* INP_INFO lock is busy, continue later */ - TW_WLOCK(V_tw_lock); tw_pcbrele(tw); break; }