From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1425167AbdEYWIG (ORCPT ); Thu, 25 May 2017 18:08:06 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39671 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S943089AbdEYWAR (ORCPT ); Thu, 25 May 2017 18:00:17 -0400 From: "Paul E. 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, bobby.prani@gmail.com, "Paul E. McKenney" , Rik van Riel Subject: [PATCH tip/core/rcu 75/88] rcu: Remove the RCU_KTHREAD_PRIO Kconfig option Date: Thu, 25 May 2017 14:59:48 -0700 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20170525215934.GA11578@linux.vnet.ibm.com> References: <20170525215934.GA11578@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17052522-0048-0000-0000-0000018F4E0D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007117; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00865574; UDB=6.00429834; IPR=6.00645396; BA=6.00005375; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015583; XFM=3.00000015; UTC=2017-05-25 22:00:12 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17052522-0049-0000-0000-0000414483AE Message-Id: <1495749601-21574-75-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-25_17:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1705250401 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Anything that can be done with the RCU_KTHREAD_PRIO Kconfig option can also be done with the rcutree.kthread_prio kernel boot parameter. This commit therefore removes this Kconfig option. Reported-by: Linus Torvalds Signed-off-by: Paul E. McKenney Cc: Frederic Weisbecker Cc: Rik van Riel --- init/Kconfig | 31 ---------------------- kernel/rcu/tree.c | 4 --- .../selftests/rcutorture/configs/rcu/TREE03 | 1 - .../selftests/rcutorture/configs/rcu/TREE03.boot | 1 + .../selftests/rcutorture/doc/TREE_RCU-kconfig.txt | 1 - 5 files changed, 1 insertion(+), 37 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index a2cfde19e8b8..6f257d51f582 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -697,37 +697,6 @@ config RCU_BOOST Say Y here if you are working with real-time apps or heavy loads Say N here if you are unsure. -config RCU_KTHREAD_PRIO - int "Real-time priority to use for RCU worker threads" - range 1 99 if RCU_BOOST - range 0 99 if !RCU_BOOST - default 1 if RCU_BOOST - default 0 if !RCU_BOOST - depends on RCU_EXPERT - help - This option specifies the SCHED_FIFO priority value that will be - assigned to the rcuc/n and rcub/n threads and is also the value - used for RCU_BOOST (if enabled). If you are working with a - real-time application that has one or more CPU-bound threads - running at a real-time priority level, you should set - RCU_KTHREAD_PRIO to a priority higher than the highest-priority - real-time CPU-bound application thread. The default RCU_KTHREAD_PRIO - value of 1 is appropriate in the common case, which is real-time - applications that do not have any CPU-bound threads. - - Some real-time applications might not have a single real-time - thread that saturates a given CPU, but instead might have - multiple real-time threads that, taken together, fully utilize - that CPU. In this case, you should set RCU_KTHREAD_PRIO to - a priority higher than the lowest-priority thread that is - conspiring to prevent the CPU from running any non-real-time - tasks. For example, if one thread at priority 10 and another - thread at priority 5 are between themselves fully consuming - the CPU time on a given CPU, then RCU_KTHREAD_PRIO should be - set to priority 6 or higher. - - Specify the real-time priority, or take the default if unsure. - config RCU_BOOST_DELAY int "Milliseconds to delay boosting after RCU grace-period start" range 0 3000 diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index bbbddd85906b..187ac3f41526 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -168,11 +168,7 @@ static void rcu_report_exp_rdp(struct rcu_state *rsp, static void sync_sched_exp_online_cleanup(int cpu); /* rcuc/rcub kthread realtime priority */ -#ifdef CONFIG_RCU_KTHREAD_PRIO -static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO; -#else /* #ifdef CONFIG_RCU_KTHREAD_PRIO */ static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0; -#endif /* #else #ifdef CONFIG_RCU_KTHREAD_PRIO */ module_param(kthread_prio, int, 0644); /* Delay in jiffies for grace-period initialization delays, debug only. */ diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 b/tools/testing/selftests/rcutorture/configs/rcu/TREE03 index 7a17c503b382..2dc31b16e506 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE03 @@ -14,6 +14,5 @@ CONFIG_RCU_FANOUT_LEAF=2 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_RCU_BOOST=y -CONFIG_RCU_KTHREAD_PRIO=2 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot index 9ef3aed126e9..5d2cc0bd50a0 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot @@ -2,3 +2,4 @@ rcutorture.onoff_interval=1 rcutorture.onoff_holdoff=30 rcutree.gp_preinit_delay=3 rcutree.gp_init_delay=3 rcutree.gp_cleanup_delay=3 +rcutree.kthread_prio=2 diff --git a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt index 1dfec4657d95..b5ea8489969a 100644 --- a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt +++ b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt @@ -16,7 +16,6 @@ CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not. CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING. CONFIG_PROVE_RCU_REPEATEDLY -- Do one. CONFIG_RCU_BOOST -- one of PREEMPT_RCU. -CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing. CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others. CONFIG_RCU_FANOUT_LEAF -- Do one non-default. CONFIG_RCU_FAST_NO_HZ -- Do one, but not with CONFIG_RCU_NOCB_CPU_ALL. -- 2.5.2