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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" Subject: [PATCH tip/core/rcu 03/41] rcu: Eliminate synchronize_rcu_mult() Date: Sun, 11 Nov 2018 11:43:32 -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: 18111119-2213-0000-0000-00000315A7DF 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=6.00578733; IPR=6.00896120; MB=3.00024114; MTD=3.00000008; XFM=3.00000015; UTC=2018-11-11 19:44:16 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18111119-2214-0000-0000-00005C386BB1 Message-Id: <20181111194410.6368-3-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=999 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 From: "Paul E. McKenney" Now that synchronize_rcu() waits for both RCU read-side critical sections and preempt-disabled regions of code, the sole caller of synchronize_rcu_mult() can be replaced by synchronize_rcu(). This patch makes this change and removes synchronize_rcu_mult(). Note that _wait_rcu_gp() still supports synchronize_rcu_mult(), and thus might be simplified in the future to take only take a single call_rcu() function rather than the current list of them. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate_wait.h | 17 ----------------- kernel/rcu/update.c | 6 ++---- kernel/sched/core.c | 2 +- 3 files changed, 3 insertions(+), 22 deletions(-) diff --git a/include/linux/rcupdate_wait.h b/include/linux/rcupdate_wait.h index 8a16c3eb3dd0..c0578ba23c1a 100644 --- a/include/linux/rcupdate_wait.h +++ b/include/linux/rcupdate_wait.h @@ -31,21 +31,4 @@ do { \ #define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__) -/** - * synchronize_rcu_mult - Wait concurrently for multiple grace periods - * @...: List of call_rcu() functions for different grace periods to wait on - * - * This macro waits concurrently for multiple types of RCU grace periods. - * For example, synchronize_rcu_mult(call_rcu, call_rcu_tasks) would wait - * on concurrent RCU and RCU-tasks grace periods. Waiting on a give SRCU - * domain requires you to write a wrapper function for that SRCU domain's - * call_srcu() function, supplying the corresponding srcu_struct. - * - * If Tiny RCU, tell _wait_rcu_gp() does not bother waiting for RCU, - * given that anywhere synchronize_rcu_mult() can be called is automatically - * a grace period. - */ -#define synchronize_rcu_mult(...) \ - _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__) - #endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */ diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index f203b94f6b5b..c729ca5e6ee2 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -335,8 +335,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, /* Initialize and register callbacks for each crcu_array element. */ for (i = 0; i < n; i++) { if (checktiny && - (crcu_array[i] == call_rcu || - crcu_array[i] == call_rcu_bh)) { + (crcu_array[i] == call_rcu)) { might_sleep(); continue; } @@ -352,8 +351,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, /* Wait for all callbacks to be invoked. */ for (i = 0; i < n; i++) { if (checktiny && - (crcu_array[i] == call_rcu || - crcu_array[i] == call_rcu_bh)) + (crcu_array[i] == call_rcu)) continue; for (j = 0; j < i; j++) if (crcu_array[j] == crcu_array[i]) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f12225f26b70..ea12ebc57840 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5788,7 +5788,7 @@ int sched_cpu_deactivate(unsigned int cpu) * * Do sync before park smpboot threads to take care the rcu boost case. */ - synchronize_rcu_mult(call_rcu, call_rcu_sched); + synchronize_rcu(); if (!sched_smp_initialized) return 0; -- 2.17.1