From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756111AbaKSPq5 (ORCPT ); Wed, 19 Nov 2014 10:46:57 -0500 Received: from mail-pa0-f49.google.com ([209.85.220.49]:48268 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756065AbaKSPqy (ORCPT ); Wed, 19 Nov 2014 10:46:54 -0500 From: "pang.xunlei" To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Steven Rostedt , Juri Lelli , "pang.xunlei" Subject: [PATCH v2 2/4] sched/deadline: Fix wrong cpudl_find() in check_preempt_equal_dl() Date: Wed, 19 Nov 2014 23:46:20 +0800 Message-Id: <1416411982-1204-2-git-send-email-pang.xunlei@linaro.org> X-Mailer: git-send-email 2.0.4 In-Reply-To: <1416411982-1204-1-git-send-email-pang.xunlei@linaro.org> References: <1416411982-1204-1-git-send-email-pang.xunlei@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In check_preempt_equal_dl(), cpudl_find() is called with a NULL later_mask, thus cpudl_find() here doesn't check cpudl.free_cpus at all. This patch takles this issue by always passing a non-NULL cpumask to cpudl_find(), and assigns later_mask in this function. Signed-off-by: pang.xunlei --- kernel/sched/cpudeadline.c | 10 ++++------ kernel/sched/deadline.c | 10 ++++++---- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index c79f0d7..c01b3aa 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -97,7 +97,7 @@ static inline int cpudl_maximum(struct cpudl *cp) * cpudl_find - find the best (later-dl) CPU in the system * @cp: the cpudl max-heap context * @p: the task - * @later_mask: a mask to fill in with the selected CPUs (or NULL) + * @later_mask: a mask to fill in with the selected CPUs (not NULL) * * Returns: int - best CPU (heap maximum if suitable) */ @@ -107,16 +107,14 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, int best_cpu = -1; const struct sched_dl_entity *dl_se = &p->dl; - if (later_mask && - cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed) && - cpumask_and(later_mask, later_mask, cpu_active_mask)) { + cpumask_and(later_mask, cpu_active_mask, &p->cpus_allowed); + if (cpumask_and(later_mask, later_mask, cp->free_cpus)) { best_cpu = cpumask_any(later_mask); goto out; } else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) && dl_time_before(dl_se->deadline, cp->elements[0].dl)) { best_cpu = cpudl_maximum(cp); - if (later_mask) - cpumask_set_cpu(best_cpu, later_mask); + cpumask_set_cpu(best_cpu, later_mask); } out: diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index bd83272..3ecf838 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -965,14 +965,18 @@ out: return cpu; } +static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask_dl); + static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p) { + struct cpumask *later_mask = this_cpu_cpumask_var_ptr(local_cpu_mask_dl); + /* * Current can't be migrated, useless to reschedule, * let's hope p can move out. */ if (rq->curr->nr_cpus_allowed == 1 || - cpudl_find(&rq->rd->cpudl, rq->curr, NULL) == -1) + cpudl_find(&rq->rd->cpudl, rq->curr, later_mask) == -1) return; /* @@ -980,7 +984,7 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p) * see if it is pushed or pulled somewhere else. */ if (p->nr_cpus_allowed != 1 && - cpudl_find(&rq->rd->cpudl, p, NULL) != -1) + cpudl_find(&rq->rd->cpudl, p, later_mask) != -1) return; resched_curr(rq); @@ -1167,8 +1171,6 @@ next_node: return NULL; } -static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask_dl); - static int find_later_rq(struct task_struct *task) { struct sched_domain *sd; -- 1.7.9.5