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McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" , Ingo Molnar Subject: [PATCH tip/core/rcu 23/41] sched: Replace synchronize_sched() with synchronize_rcu() Date: Sun, 11 Nov 2018 11:43:52 -0800 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181111194104.GA4787@linux.ibm.com> References: <20181111194104.GA4787@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18111119-0068-0000-0000-0000035E482C X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010028; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000270; SDB=6.01116019; UDB=6.00578732; IPR=6.00896120; MB=3.00024114; MTD=3.00000008; XFM=3.00000015; UTC=2018-11-11 19:44:17 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18111119-0069-0000-0000-000046644C68 Message-Id: <20181111194410.6368-23-paulmck@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-11_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=927 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1811110188 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that synchronize_rcu() waits for preempt-disable regions of code as well as RCU read-side critical sections, synchronize_sched() can be replaced by synchronize_rcu(). This commit therefore makes this change. Signed-off-by: Paul E. McKenney Cc: Ingo Molnar Cc: Peter Zijlstra --- kernel/sched/cpufreq.c | 4 ++-- kernel/sched/cpufreq_schedutil.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c index 5e54cbcae673..90fee8e01280 100644 --- a/kernel/sched/cpufreq.c +++ b/kernel/sched/cpufreq.c @@ -51,8 +51,8 @@ EXPORT_SYMBOL_GPL(cpufreq_add_update_util_hook); * * Clear the update_util_data pointer for the given CPU. * - * Callers must use RCU-sched callbacks to free any memory that might be - * accessed via the old update_util_data pointer or invoke synchronize_sched() + * Callers must use RCU callbacks to free any memory that might be + * accessed via the old update_util_data pointer or invoke synchronize_rcu() * right after this function to avoid use-after-free. */ void cpufreq_remove_update_util_hook(int cpu) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 3fffad3bc8a8..6a1bb76afbd1 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -839,7 +839,7 @@ static void sugov_stop(struct cpufreq_policy *policy) for_each_cpu(cpu, policy->cpus) cpufreq_remove_update_util_hook(cpu); - synchronize_sched(); + synchronize_rcu(); if (!policy->fast_switch_enabled) { irq_work_sync(&sg_policy->irq_work); -- 2.17.1