From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f177.google.com (mail-ie0-f177.google.com [209.85.223.177]) by dpdk.org (Postfix) with ESMTP id B531BC3E8 for ; Fri, 24 Jul 2015 00:43:05 +0200 (CEST) Received: by iehx8 with SMTP id x8so5372822ieh.3 for ; Thu, 23 Jul 2015 15:43:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=WZsrWwbeAgzC/8Cy2XYcgaW0I40QSf4E36tt8SWwgU0=; b=zLZzkRZOpoGMq6QCFqiYwVRqPL9JhB6BImYjPf0Yp9emeVA7E4uVuPdydBnGaG1sbL jsPmq0R/irGuVyn18k/rzihBOKenc4JNHRkvb96wUXS27xlrRgD5Hw0KkNDEb/V1GUSM FBvb36OYIGqpEzxth4N4JSN2n99wAaSSTlVIktpsabtXG9Sopy4d9EzzptxMe1fCiBlF 4GOmxELvNT3HJ9VhpWxmL6dwcrPdP9hCmdNn/x0eZwWzskVflgRZ7XG3fmGtAqgRmkzS rhIXy89uZNcCH1L1X0T3rFqDiWVK1rz+nNkmSExYXnL02Jgu5jFdb3/1LjnRbEosa6Sj zwAw== X-Received: by 10.50.27.39 with SMTP id q7mr851926igg.73.1437691385267; Thu, 23 Jul 2015 15:43:05 -0700 (PDT) Received: from localhost.localdomain ([23.79.237.14]) by smtp.gmail.com with ESMTPSA id j20sm254990igt.16.2015.07.23.15.43.04 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Jul 2015 15:43:04 -0700 (PDT) From: rsanford2@gmail.com To: dev@dpdk.org Date: Thu, 23 Jul 2015 18:42:27 -0400 Message-Id: <1437691347-58708-4-git-send-email-rsanford2@gmail.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1437691347-58708-1-git-send-email-rsanford2@gmail.com> References: <1437691347-58708-1-git-send-email-rsanford2@gmail.com> Subject: [dpdk-dev] [PATCH 3/3] timer: fix race condition in rte_timer_manage() X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Jul 2015 22:43:06 -0000 From: Robert Sanford Signed-off-by: Robert Sanford --- lib/librte_timer/rte_timer.c | 45 +++++++++++++++++++++++++++-------------- 1 files changed, 29 insertions(+), 16 deletions(-) diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c index 8e9243a..51e6038 100644 --- a/lib/librte_timer/rte_timer.c +++ b/lib/librte_timer/rte_timer.c @@ -504,6 +504,7 @@ void rte_timer_manage(void) { union rte_timer_status status; struct rte_timer *tim, *next_tim; + struct rte_timer *run_first_tim, **pprev; unsigned lcore_id = rte_lcore_id(); struct rte_timer *prev[MAX_SKIPLIST_DEPTH + 1]; uint64_t cur_time; @@ -531,8 +532,10 @@ void rte_timer_manage(void) /* if nothing to do just unlock and return */ if (priv_timer[lcore_id].pending_head.sl_next[0] == NULL || - priv_timer[lcore_id].pending_head.sl_next[0]->expire > cur_time) - goto done; + priv_timer[lcore_id].pending_head.sl_next[0]->expire > cur_time) { + rte_spinlock_unlock(&priv_timer[lcore_id].list_lock); + return; + } /* save start of list of expired timers */ tim = priv_timer[lcore_id].pending_head.sl_next[0]; @@ -546,24 +549,40 @@ void rte_timer_manage(void) prev[i] ->sl_next[i] = NULL; } - /* now scan expired list and call callbacks */ + /* transition run-list from PENDING to RUNNING */ + run_first_tim = tim; + pprev = &run_first_tim; + for ( ; tim != NULL; tim = next_tim) { next_tim = tim->sl_next[0]; ret = timer_set_running_state(tim); + if (likely(ret == 0)) { + pprev = &tim->sl_next[0]; + } else { + /* another core is trying to re-config this one, + * remove it from local expired list and put it + * back on the priv_timer[] skip list */ + *pprev = next_tim; + timer_add(tim, lcore_id, 1); + } + } - /* this timer was not pending, continue */ - if (ret < 0) - continue; + /* update the next to expire timer value */ + priv_timer[lcore_id].pending_head.expire = + (priv_timer[lcore_id].pending_head.sl_next[0] == NULL) ? 0 : + priv_timer[lcore_id].pending_head.sl_next[0]->expire; - rte_spinlock_unlock(&priv_timer[lcore_id].list_lock); + rte_spinlock_unlock(&priv_timer[lcore_id].list_lock); + /* now scan expired list and call callbacks */ + for (tim = run_first_tim; tim != NULL; tim = next_tim) { + next_tim = tim->sl_next[0]; priv_timer[lcore_id].updated = 0; /* execute callback function with list unlocked */ tim->f(tim, tim->arg); - rte_spinlock_lock(&priv_timer[lcore_id].list_lock); __TIMER_STAT_ADD(pending, -1); /* the timer was stopped or reloaded by the callback * function, we have nothing to do here */ @@ -579,6 +598,7 @@ void rte_timer_manage(void) } else { /* keep it in list and mark timer as pending */ + rte_spinlock_lock(&priv_timer[lcore_id].list_lock); status.state = RTE_TIMER_PENDING; __TIMER_STAT_ADD(pending, 1); status.owner = (int16_t)lcore_id; @@ -586,16 +606,9 @@ void rte_timer_manage(void) tim->status.u32 = status.u32; __rte_timer_reset(tim, cur_time + tim->period, tim->period, lcore_id, tim->f, tim->arg, 1); + rte_spinlock_unlock(&priv_timer[lcore_id].list_lock); } } - - /* update the next to expire timer value */ - priv_timer[lcore_id].pending_head.expire = - (priv_timer[lcore_id].pending_head.sl_next[0] == NULL) ? 0 : - priv_timer[lcore_id].pending_head.sl_next[0]->expire; -done: - /* job finished, unlock the list lock */ - rte_spinlock_unlock(&priv_timer[lcore_id].list_lock); } /* dump statistics about timers */ -- 1.7.1