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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" , Tejun Heo , Jens Axboe , Dennis Zhou , Johannes Weiner , "Dennis Zhou (Facebook)" Subject: [PATCH tip/core/rcu 36/41] cgroups: Replace synchronize_sched() with synchronize_rcu() Date: Sun, 11 Nov 2018 11:44:05 -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: 18111119-0040-0000-0000-0000049088D5 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=6.00577119; IPR=6.00896119; MB=3.00024114; MTD=3.00000008; XFM=3.00000015; UTC=2018-11-11 19:44:19 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18111119-0041-0000-0000-000008999183 Message-Id: <20181111194410.6368-36-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=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=625 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, even though it is but a comment. Signed-off-by: Paul E. McKenney Cc: Tejun Heo Cc: Jens Axboe Cc: Dennis Zhou Cc: Johannes Weiner Cc: "Dennis Zhou (Facebook)" --- kernel/cgroup/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 6aaf5dd5383b..7a8429f8e280 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5343,7 +5343,7 @@ int __init cgroup_init(void) cgroup_rstat_boot(); /* - * The latency of the synchronize_sched() is too high for cgroups, + * The latency of the synchronize_rcu() is too high for cgroups, * avoid it at the cost of forcing all readers into the slow path. */ rcu_sync_enter_start(&cgroup_threadgroup_rwsem.rss); -- 2.17.1