[tip:smp/hotplug] cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

[tip-bot for Sebastian Andrzej Siewior]

Commit-ID:  210e21331fc3a396af640cec652be769d146e49f
Gitweb: http://git.kernel.org/tip/210e21331fc3a396af640cec652be769d146e49f
Author: Sebastian Andrzej Siewior 
AuthorDate: Wed, 24 May 2017 10:15:28 +0200
Committer:  Thomas Gleixner 
CommitDate: Fri, 26 May 2017 10:10:42 +0200

cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_cpuslocked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Tested-by: Paul E. McKenney 
Acked-by: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170524081548.423292...@linutronix.de

---
 kernel/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index e4389ac..142d889 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -701,7 +701,7 @@ static int takedown_cpu(unsigned int cpu)
/*
 * So now all preempt/rcu users must observe !cpu_active().
 */
-   err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
+   err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU refused to die */
irq_unlock_sparse();

[tip:smp/hotplug] cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

[tip-bot for Sebastian Andrzej Siewior]

Commit-ID:  210e21331fc3a396af640cec652be769d146e49f
Gitweb: http://git.kernel.org/tip/210e21331fc3a396af640cec652be769d146e49f
Author: Sebastian Andrzej Siewior 
AuthorDate: Wed, 24 May 2017 10:15:28 +0200
Committer:  Thomas Gleixner 
CommitDate: Fri, 26 May 2017 10:10:42 +0200

cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_cpuslocked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Tested-by: Paul E. McKenney 
Acked-by: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170524081548.423292...@linutronix.de

---
 kernel/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index e4389ac..142d889 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -701,7 +701,7 @@ static int takedown_cpu(unsigned int cpu)
/*
 * So now all preempt/rcu users must observe !cpu_active().
 */
-   err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
+   err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU refused to die */
irq_unlock_sparse();

[tip:smp/hotplug] cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

[tip-bot for Sebastian Andrzej Siewior]

Commit-ID:  cdcb496b285dc8e9c544107d42bd60e5bc2feffa
Gitweb: http://git.kernel.org/tip/cdcb496b285dc8e9c544107d42bd60e5bc2feffa
Author: Sebastian Andrzej Siewior 
AuthorDate: Tue, 18 Apr 2017 19:04:56 +0200
Committer:  Thomas Gleixner 
CommitDate: Thu, 20 Apr 2017 13:08:55 +0200

cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_cpuslocked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170418170553.531067...@linutronix.de

---
 kernel/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 92e5a91..f932e68 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -701,7 +701,7 @@ static int takedown_cpu(unsigned int cpu)
/*
 * So now all preempt/rcu users must observe !cpu_active().
 */
-   err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
+   err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU refused to die */
irq_unlock_sparse();

[tip:smp/hotplug] cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

[tip-bot for Sebastian Andrzej Siewior]

Commit-ID:  cdcb496b285dc8e9c544107d42bd60e5bc2feffa
Gitweb: http://git.kernel.org/tip/cdcb496b285dc8e9c544107d42bd60e5bc2feffa
Author: Sebastian Andrzej Siewior 
AuthorDate: Tue, 18 Apr 2017 19:04:56 +0200
Committer:  Thomas Gleixner 
CommitDate: Thu, 20 Apr 2017 13:08:55 +0200

cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_cpuslocked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170418170553.531067...@linutronix.de

---
 kernel/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 92e5a91..f932e68 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -701,7 +701,7 @@ static int takedown_cpu(unsigned int cpu)
/*
 * So now all preempt/rcu users must observe !cpu_active().
 */
-   err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
+   err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU refused to die */
irq_unlock_sparse();