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
Cc: linux-arch@vger.kernel.org, nikunj@linux.vnet.ibm.com,
zhong@linux.vnet.ibm.com, linux-pm@vger.kernel.org,
fweisbec@gmail.com, linux-kernel@vger.kernel.org,
rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com,
sbw@mit.edu, wangyun@linux.vnet.ibm.com,
"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
netdev@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 19/45] irq: Use get/put_online_cpus_atomic() to prevent CPU offline
Date: Wed, 26 Jun 2013 01:58:49 +0530 [thread overview]
Message-ID: <20130625202849.16593.84150.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20130625202452.16593.22810.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/irq/manage.c | 7 +++++++
kernel/irq/proc.c | 3 +++
2 files changed, 10 insertions(+)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e16caa8..4d89f19 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -18,6 +18,7 @@
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/task_work.h>
+#include <linux/cpu.h>
#include "internals.h"
@@ -202,9 +203,11 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
if (!desc)
return -EINVAL;
+ get_online_cpus_atomic();
raw_spin_lock_irqsave(&desc->lock, flags);
ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
raw_spin_unlock_irqrestore(&desc->lock, flags);
+ put_online_cpus_atomic();
return ret;
}
@@ -343,9 +346,11 @@ int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
unsigned long flags;
int ret;
+ get_online_cpus_atomic();
raw_spin_lock_irqsave(&desc->lock, flags);
ret = setup_affinity(irq, desc, mask);
raw_spin_unlock_irqrestore(&desc->lock, flags);
+ put_online_cpus_atomic();
return ret;
}
@@ -1128,7 +1133,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
}
/* Set default affinity mask once everything is setup */
+ get_online_cpus_atomic();
setup_affinity(irq, desc, mask);
+ put_online_cpus_atomic();
} else if (new->flags & IRQF_TRIGGER_MASK) {
unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 19ed5c4..47f9a74 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -7,6 +7,7 @@
*/
#include <linux/irq.h>
+#include <linux/cpu.h>
#include <linux/gfp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
@@ -441,6 +442,7 @@ int show_interrupts(struct seq_file *p, void *v)
if (!desc)
return 0;
+ get_online_cpus_atomic();
raw_spin_lock_irqsave(&desc->lock, flags);
for_each_online_cpu(j)
any_count |= kstat_irqs_cpu(i, j);
@@ -477,6 +479,7 @@ int show_interrupts(struct seq_file *p, void *v)
seq_putc(p, '\n');
out:
raw_spin_unlock_irqrestore(&desc->lock, flags);
+ put_online_cpus_atomic();
return 0;
}
#endif
next prev parent reply other threads:[~2013-06-25 20:32 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-25 20:25 [PATCH v2 00/45] CPU hotplug: stop_machine()-free CPU hotplug, part 1 Srivatsa S. Bhat
2013-06-25 20:25 ` [PATCH v2 01/45] CPU hotplug: Provide APIs to prevent CPU offline from atomic context Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 02/45] CPU hotplug: Clarify the usage of different synchronization APIs Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 03/45] Documentation, CPU hotplug: Recommend usage of get/put_online_cpus_atomic() Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 04/45] CPU hotplug: Add infrastructure to check lacking hotplug synchronization Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 05/45] CPU hotplug: Protect set_cpu_online() to avoid false-positives Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 06/45] CPU hotplug: Sprinkle debugging checks to catch locking bugs Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 07/45] CPU hotplug: Expose the new debug config option Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 08/45] CPU hotplug: Convert preprocessor macros to static inline functions Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 09/45] smp: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 10/45] sched/core: " Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 11/45] migration: Use raw_spin_lock/unlock since interrupts are already disabled Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 12/45] sched/fair: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 13/45] timer: " Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 14/45] sched/rt: " Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 15/45] rcu: " Srivatsa S. Bhat
2013-06-25 22:00 ` Paul E. McKenney
2013-06-26 14:09 ` Srivatsa S. Bhat
2013-06-26 14:29 ` David Laight
2013-06-26 14:34 ` Paul E. McKenney
2013-06-26 14:51 ` Steven Rostedt
2013-06-26 15:21 ` Tejun Heo
2013-06-26 15:33 ` Steven Rostedt
2013-06-26 17:29 ` Tejun Heo
2013-06-26 18:28 ` Srivatsa S. Bhat
2013-06-26 21:34 ` Tejun Heo
2013-06-27 6:53 ` Srivatsa S. Bhat
2013-06-26 18:22 ` Srivatsa S. Bhat
2013-06-27 8:54 ` David Laight
2013-06-27 10:06 ` Srivatsa S. Bhat
2013-06-26 14:45 ` Paul E. McKenney
2013-06-26 18:18 ` Srivatsa S. Bhat
2013-06-26 14:33 ` Paul E. McKenney
2013-06-25 20:28 ` [PATCH v2 16/45] tick-broadcast: " Srivatsa S. Bhat
2013-06-25 20:28 ` [PATCH v2 17/45] time/clocksource: " Srivatsa S. Bhat
2013-06-25 20:28 ` [PATCH v2 18/45] softirq: " Srivatsa S. Bhat
2013-06-25 20:28 ` Srivatsa S. Bhat [this message]
2013-06-25 20:29 ` [PATCH v2 20/45] net: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 21/45] block: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 22/45] percpu_counter: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 23/45] infiniband: ehca: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 24/45] [SCSI] fcoe: " Srivatsa S. Bhat
2013-06-25 20:30 ` [PATCH v2 25/45] staging/octeon: " Srivatsa S. Bhat
2013-06-25 20:45 ` Greg Kroah-Hartman
2013-06-25 20:30 ` [PATCH v2 26/45] x86: " Srivatsa S. Bhat
2013-06-25 20:30 ` [PATCH v2 27/45] perf/x86: " Srivatsa S. Bhat
2013-06-25 20:30 ` [PATCH v2 28/45] KVM: " Srivatsa S. Bhat
2013-06-26 8:20 ` Paolo Bonzini
2013-06-25 20:30 ` [PATCH v2 29/45] kvm/vmx: " Srivatsa S. Bhat
2013-06-26 7:46 ` Paolo Bonzini
2013-06-26 8:06 ` Srivatsa S. Bhat
2013-06-26 8:23 ` Paolo Bonzini
2013-06-26 8:41 ` Srivatsa S. Bhat
2013-06-26 8:57 ` Paolo Bonzini
2013-06-25 20:30 ` [PATCH v2 30/45] x86/xen: " Srivatsa S. Bhat
2013-06-25 20:31 ` [PATCH v2 31/45] alpha/smp: " Srivatsa S. Bhat
2013-06-25 20:31 ` [PATCH v2 32/45] blackfin/smp: " Srivatsa S. Bhat
2013-06-25 20:31 ` [PATCH v2 33/45] cris/smp: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 34/45] hexagon/smp: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 35/45] ia64: irq, perfmon: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 36/45] ia64: smp, tlb: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 37/45] m32r: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 38/45] MIPS: " Srivatsa S. Bhat
2013-06-26 13:39 ` Ralf Baechle
2013-06-27 7:08 ` Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 39/45] mn10300: " Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 40/45] powerpc, irq: Use GFP_ATOMIC allocations in atomic context Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 41/45] powerpc: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 42/45] powerpc: Use get/put_online_cpus_atomic() to avoid false-positive warning Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 43/45] sh: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 44/45] sparc: " Srivatsa S. Bhat
2013-06-25 20:34 ` [PATCH v2 45/45] tile: " Srivatsa S. Bhat
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