Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756170AbbGQXfi (ORCPT ); Fri, 17 Jul 2015 19:35:38 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:48834 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754006AbbGQX3d (ORCPT ); Fri, 17 Jul 2015 19:29:33 -0400 X-Helo: d03dlp02.boulder.ibm.com X-MailFrom: paulmck@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org 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, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 02/19] rcu: Remove CONFIG_RCU_CPU_STALL_INFO Date: Fri, 17 Jul 2015 16:29:07 -0700 Message-Id: <1437175764-24096-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1437175764-24096-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150717232901.GA22511@linux.vnet.ibm.com> <1437175764-24096-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15071723-0009-0000-0000-00000C918EB0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13475 Lines: 344 From: "Paul E. McKenney" The CONFIG_RCU_CPU_STALL_INFO has been default-y for a couple of releases with no complaints, so it is time to eliminate this Kconfig option entirely, so that the long-form RCU CPU stall warnings cannot be disabled. This commit does just that. Signed-off-by: Paul E. McKenney --- Documentation/RCU/stallwarn.txt | 12 +----- kernel/rcu/tree.h | 4 -- kernel/rcu/tree_plugin.h | 45 ---------------------- lib/Kconfig.debug | 14 ------- .../selftests/rcutorture/configs/rcu/TREE01 | 1 - .../selftests/rcutorture/configs/rcu/TREE02 | 1 - .../selftests/rcutorture/configs/rcu/TREE02-T | 1 - .../selftests/rcutorture/configs/rcu/TREE03 | 1 - .../selftests/rcutorture/configs/rcu/TREE04 | 1 - .../selftests/rcutorture/configs/rcu/TREE05 | 1 - .../selftests/rcutorture/configs/rcu/TREE06 | 1 - .../selftests/rcutorture/configs/rcu/TREE07 | 1 - .../selftests/rcutorture/configs/rcu/TREE08 | 1 - .../selftests/rcutorture/configs/rcu/TREE08-T | 1 - .../selftests/rcutorture/configs/rcu/TREE09 | 1 - .../selftests/rcutorture/doc/TREE_RCU-kconfig.txt | 1 - 16 files changed, 2 insertions(+), 85 deletions(-) diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt index b57c0c1cdac6..046f32637b95 100644 --- a/Documentation/RCU/stallwarn.txt +++ b/Documentation/RCU/stallwarn.txt @@ -26,12 +26,6 @@ CONFIG_RCU_CPU_STALL_TIMEOUT Stall-warning messages may be enabled and disabled completely via /sys/module/rcupdate/parameters/rcu_cpu_stall_suppress. -CONFIG_RCU_CPU_STALL_INFO - - This kernel configuration parameter causes the stall warning to - print out additional per-CPU diagnostic information, including - information on scheduling-clock ticks and RCU's idle-CPU tracking. - RCU_STALL_DELAY_DELTA Although the lockdep facility is extremely useful, it does add @@ -101,15 +95,13 @@ interact. Please note that it is not possible to entirely eliminate this sort of false positive without resorting to things like stop_machine(), which is overkill for this sort of problem. -If the CONFIG_RCU_CPU_STALL_INFO kernel configuration parameter is set, -more information is printed with the stall-warning message, for example: +Recent kernels will print a long form of the stall-warning message: INFO: rcu_preempt detected stall on CPU 0: (63959 ticks this GP) idle=241/3fffffffffffffff/0 softirq=82/543 (t=65000 jiffies) -In kernels with CONFIG_RCU_FAST_NO_HZ, even more information is -printed: +In kernels with CONFIG_RCU_FAST_NO_HZ, more information is printed: INFO: rcu_preempt detected stall on CPU 0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 nonlazy_posted: 25 .D diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index faee5242d6ff..7c0b09d754a1 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -288,12 +288,10 @@ struct rcu_data { bool gpwrap; /* Possible gpnum/completed wrap. */ struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ unsigned long grpmask; /* Mask to apply to leaf qsmask. */ -#ifdef CONFIG_RCU_CPU_STALL_INFO unsigned long ticks_this_gp; /* The number of scheduling-clock */ /* ticks this CPU has handled */ /* during and after the last grace */ /* period it is aware of. */ -#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */ /* 2) batch handling */ /* @@ -388,9 +386,7 @@ struct rcu_data { #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ /* 8) RCU CPU stall data. */ -#ifdef CONFIG_RCU_CPU_STALL_INFO unsigned int softirq_snap; /* Snapshot of softirq activity. */ -#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */ int cpu; struct rcu_state *rsp; diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 7234f03e0aa2..ef41c1b04ba6 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -82,8 +82,6 @@ static void __init rcu_bootup_announce_oddness(void) pr_info("\tRCU lockdep checking is enabled.\n"); if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_RUNNABLE)) pr_info("\tRCU torture testing starts during boot.\n"); - if (IS_ENABLED(CONFIG_RCU_CPU_STALL_INFO)) - pr_info("\tAdditional per-CPU info printed with stalls.\n"); if (RCU_NUM_LVLS >= 4) pr_info("\tFour(or more)-level hierarchy is enabled.\n"); if (RCU_FANOUT_LEAF != 16) @@ -418,8 +416,6 @@ static void rcu_print_detail_task_stall(struct rcu_state *rsp) rcu_print_detail_task_stall_rnp(rnp); } -#ifdef CONFIG_RCU_CPU_STALL_INFO - static void rcu_print_task_stall_begin(struct rcu_node *rnp) { pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):", @@ -431,18 +427,6 @@ static void rcu_print_task_stall_end(void) pr_cont("\n"); } -#else /* #ifdef CONFIG_RCU_CPU_STALL_INFO */ - -static void rcu_print_task_stall_begin(struct rcu_node *rnp) -{ -} - -static void rcu_print_task_stall_end(void) -{ -} - -#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_INFO */ - /* * Scan the current list of tasks blocked within RCU read-side critical * sections, printing out the tid of each. @@ -1685,8 +1669,6 @@ early_initcall(rcu_register_oom_notifier); #endif /* #else #if !defined(CONFIG_RCU_FAST_NO_HZ) */ -#ifdef CONFIG_RCU_CPU_STALL_INFO - #ifdef CONFIG_RCU_FAST_NO_HZ static void print_cpu_stall_fast_no_hz(char *cp, int cpu) @@ -1775,33 +1757,6 @@ static void increment_cpu_stall_ticks(void) raw_cpu_inc(rsp->rda->ticks_this_gp); } -#else /* #ifdef CONFIG_RCU_CPU_STALL_INFO */ - -static void print_cpu_stall_info_begin(void) -{ - pr_cont(" {"); -} - -static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) -{ - pr_cont(" %d", cpu); -} - -static void print_cpu_stall_info_end(void) -{ - pr_cont("} "); -} - -static void zero_cpu_stall_ticks(struct rcu_data *rdp) -{ -} - -static void increment_cpu_stall_ticks(void) -{ -} - -#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_INFO */ - #ifdef CONFIG_RCU_NOCB_CPU /* diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index e2894b23efb6..8a34205d6922 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1353,20 +1353,6 @@ config RCU_CPU_STALL_TIMEOUT RCU grace period persists, additional CPU stall warnings are printed at more widely spaced intervals. -config RCU_CPU_STALL_INFO - bool "Print additional diagnostics on RCU CPU stall" - depends on (TREE_RCU || PREEMPT_RCU) && DEBUG_KERNEL - default y - help - For each stalled CPU that is aware of the current RCU grace - period, print out additional per-CPU diagnostic information - regarding scheduling-clock ticks, idle state, and, - for RCU_FAST_NO_HZ kernels, idle-entry state. - - Say N if you are unsure. - - Say Y if you want to enable such diagnostics. - config RCU_TRACE bool "Enable tracing for RCU" depends on DEBUG_KERNEL diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 b/tools/testing/selftests/rcutorture/configs/rcu/TREE01 index 8e9137f66831..f572b873c620 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01 @@ -13,7 +13,6 @@ CONFIG_MAXSMP=y CONFIG_RCU_NOCB_CPU=y CONFIG_RCU_NOCB_CPU_ZERO=y CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02 b/tools/testing/selftests/rcutorture/configs/rcu/TREE02 index aeea6a204d14..ef6a22c44dea 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02 @@ -17,7 +17,6 @@ CONFIG_RCU_FANOUT_LEAF=3 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T index 2ac9e68ea3d1..917d2517b5b5 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T @@ -17,6 +17,5 @@ CONFIG_RCU_FANOUT_LEAF=3 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 b/tools/testing/selftests/rcutorture/configs/rcu/TREE03 index 72aa7d87ea99..7a17c503b382 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE03 @@ -13,7 +13,6 @@ CONFIG_RCU_FANOUT=2 CONFIG_RCU_FANOUT_LEAF=2 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=y CONFIG_RCU_KTHREAD_PRIO=2 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 b/tools/testing/selftests/rcutorture/configs/rcu/TREE04 index 3f5112751cda..39a2c6d7d7ec 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE04 @@ -17,6 +17,5 @@ CONFIG_RCU_FANOUT=4 CONFIG_RCU_FANOUT_LEAF=4 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 b/tools/testing/selftests/rcutorture/configs/rcu/TREE05 index c04dfea6fd21..1257d3227b1e 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE05 @@ -17,6 +17,5 @@ CONFIG_RCU_NOCB_CPU_NONE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y #CHECK#CONFIG_PROVE_RCU=y -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE06 b/tools/testing/selftests/rcutorture/configs/rcu/TREE06 index f51d2c73a68e..d3e456b74cbe 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE06 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE06 @@ -18,6 +18,5 @@ CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y #CHECK#CONFIG_PROVE_RCU=y -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=y CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE07 b/tools/testing/selftests/rcutorture/configs/rcu/TREE07 index f422af4ff5a3..3956b4131f72 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE07 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE07 @@ -17,6 +17,5 @@ CONFIG_RCU_FANOUT=2 CONFIG_RCU_FANOUT_LEAF=2 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08 index a24d2ca30646..bb9b0c1a23c2 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08 @@ -19,7 +19,6 @@ CONFIG_RCU_NOCB_CPU_ALL=y CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_PROVE_LOCKING=y #CHECK#CONFIG_PROVE_RCU=y -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T index b2b8cea69dc9..2ad13f0d29cc 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T @@ -17,6 +17,5 @@ CONFIG_RCU_FANOUT_LEAF=2 CONFIG_RCU_NOCB_CPU=y CONFIG_RCU_NOCB_CPU_ALL=y CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 index aa4ed08d999d..6710e749d9de 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 @@ -13,7 +13,6 @@ CONFIG_SUSPEND=n CONFIG_HIBERNATION=n CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n #CHECK#CONFIG_RCU_EXPERT=n diff --git a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt index b24c0004fc49..657f3a035488 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_RCU_BOOST -- one of PREEMPT_RCU. CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing. -CONFIG_RCU_CPU_STALL_INFO -- Now default, avoid at least twice. 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. -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/