From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org,
oleg@redhat.com, paulmck@linux.vnet.ibm.com,
rusty@rustcorp.com.au, mingo@kernel.org,
akpm@linux-foundation.org, namhyung@kernel.org,
walken@google.com, vincent.guittot@linaro.org,
laijs@cn.fujitsu.com, David.Laight@aculab.com
Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com,
xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu,
fweisbec@gmail.com, zhong@linux.vnet.ibm.com,
nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com,
linux-pm@vger.kernel.org, linux-arch@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Subject: [PATCH v3 14/45] timer: Use get/put_online_cpus_atomic() to prevent CPU offline
Date: Fri, 28 Jun 2013 01:24:46 +0530 [thread overview]
Message-ID: <20130627195446.29830.13065.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com>
Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.
Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---
kernel/timer.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/timer.c b/kernel/timer.c
index 15ffdb3..5db594c 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -729,6 +729,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
timer_stats_timer_set_start_info(timer);
BUG_ON(!timer->function);
+ get_online_cpus_atomic();
base = lock_timer_base(timer, &flags);
ret = detach_if_pending(timer, base, false);
@@ -768,6 +769,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
out_unlock:
spin_unlock_irqrestore(&base->lock, flags);
+ put_online_cpus_atomic();
return ret;
}
@@ -926,6 +928,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
timer_stats_timer_set_start_info(timer);
BUG_ON(timer_pending(timer) || !timer->function);
+ get_online_cpus_atomic();
spin_lock_irqsave(&base->lock, flags);
timer_set_base(timer, base);
debug_activate(timer, timer->expires);
@@ -940,6 +943,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
*/
wake_up_nohz_cpu(cpu);
spin_unlock_irqrestore(&base->lock, flags);
+ put_online_cpus_atomic();
}
EXPORT_SYMBOL_GPL(add_timer_on);
next prev parent reply other threads:[~2013-06-27 19:58 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-27 19:52 [PATCH v3 00/45] CPU hotplug: stop_machine()-free CPU hotplug, part 1 Srivatsa S. Bhat
2013-06-27 19:52 ` [PATCH v3 01/45] CPU hotplug: Provide APIs to prevent CPU offline from atomic context Srivatsa S. Bhat
2013-06-27 19:52 ` [PATCH v3 02/45] CPU hotplug: Clarify the usage of different synchronization APIs Srivatsa S. Bhat
2013-06-27 19:52 ` [PATCH v3 03/45] Documentation, CPU hotplug: Recommend usage of get/put_online_cpus_atomic() Srivatsa S. Bhat
2013-06-27 19:53 ` [PATCH v3 04/45] CPU hotplug: Add infrastructure to check lacking hotplug synchronization Srivatsa S. Bhat
2013-06-27 19:53 ` [PATCH v3 05/45] CPU hotplug: Protect set_cpu_online() to avoid false-positives Srivatsa S. Bhat
2013-06-27 19:53 ` [PATCH v3 06/45] CPU hotplug: Sprinkle debugging checks to catch locking bugs Srivatsa S. Bhat
2013-06-27 19:53 ` [PATCH v3 07/45] CPU hotplug: Add _nocheck() variants of accessor functions Srivatsa S. Bhat
2013-06-27 19:53 ` [PATCH v3 08/45] CPU hotplug: Expose the new debug config option Srivatsa S. Bhat
2013-06-27 19:54 ` [PATCH v3 09/45] CPU hotplug: Convert preprocessor macros to static inline functions Srivatsa S. Bhat
2013-06-27 19:54 ` [PATCH v3 10/45] smp: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-07-02 5:32 ` Michael Wang
2013-07-02 8:25 ` Srivatsa S. Bhat
2013-07-02 8:47 ` Michael Wang
2013-07-02 9:51 ` Srivatsa S. Bhat
2013-07-02 10:08 ` Michael Wang
2013-06-27 19:54 ` [PATCH v3 11/45] sched/core: " Srivatsa S. Bhat
2013-06-27 19:54 ` [PATCH v3 12/45] migration: Use raw_spin_lock/unlock since interrupts are already disabled Srivatsa S. Bhat
2013-06-27 19:54 ` [PATCH v3 13/45] sched/fair: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-27 19:54 ` Srivatsa S. Bhat [this message]
2013-06-27 19:54 ` [PATCH v3 15/45] sched/rt: " Srivatsa S. Bhat
2013-06-27 19:55 ` [PATCH v3 16/45] rcu: Use cpu_is_offline_nocheck() to avoid false-positive warnings Srivatsa S. Bhat
2013-06-27 20:12 ` Paul E. McKenney
2013-06-27 19:55 ` [PATCH v3 17/45] tick-broadcast: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-27 19:55 ` [PATCH v3 18/45] time/clocksource: " Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 19/45] softirq: " Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 20/45] irq: " Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 21/45] net: " Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 22/45] block: " Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 23/45] percpu_counter: Use _nocheck version of for_each_online_cpu() Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 24/45] infiniband: ehca: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-27 19:56 ` [PATCH v3 25/45] [SCSI] fcoe: " Srivatsa S. Bhat
2013-06-27 19:57 ` [PATCH v3 26/45] staging/octeon: " Srivatsa S. Bhat
2013-06-27 19:57 ` [PATCH v3 27/45] x86: " Srivatsa S. Bhat
2013-06-27 19:57 ` [PATCH v3 28/45] perf/x86: " Srivatsa S. Bhat
2013-06-27 19:57 ` [PATCH v3 29/45] KVM: " Srivatsa S. Bhat
2013-06-27 19:57 ` [PATCH v3 30/45] x86/xen: " Srivatsa S. Bhat
2013-06-27 19:57 ` [PATCH v3 31/45] alpha/smp: " Srivatsa S. Bhat
2013-06-27 19:58 ` [PATCH v3 32/45] blackfin/smp: " Srivatsa S. Bhat
2013-06-27 19:58 ` [PATCH v3 33/45] cris/smp: " Srivatsa S. Bhat
2013-06-27 19:58 ` [PATCH v3 34/45] hexagon/smp: " Srivatsa S. Bhat
2013-06-27 19:58 ` [PATCH v3 35/45] ia64: irq, perfmon: " Srivatsa S. Bhat
2013-06-27 19:59 ` [PATCH v3 36/45] ia64: smp, tlb: " Srivatsa S. Bhat
2013-06-27 19:59 ` [PATCH v3 37/45] m32r: " Srivatsa S. Bhat
2013-06-27 19:59 ` [PATCH v3 38/45] MIPS: " Srivatsa S. Bhat
2013-06-27 19:59 ` [PATCH v3 39/45] mn10300: " Srivatsa S. Bhat
2013-06-27 19:59 ` [PATCH v3 40/45] powerpc, irq: Use GFP_ATOMIC allocations in atomic context Srivatsa S. Bhat
2013-06-27 20:00 ` [PATCH v3 41/45] powerpc: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-27 20:00 ` [PATCH v3 42/45] powerpc: Use get/put_online_cpus_atomic() to avoid false-positive warning Srivatsa S. Bhat
2013-06-27 20:00 ` [PATCH v3 43/45] sh: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-27 20:00 ` [PATCH v3 44/45] sparc: " Srivatsa S. Bhat
2013-06-27 20:00 ` [PATCH v3 45/45] tile: " Srivatsa S. Bhat
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