* [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable
@ 2022-01-25 3:39 Pingfan Liu
2022-01-25 16:29 ` Valentin Schneider
0 siblings, 1 reply; 5+ messages in thread
From: Pingfan Liu @ 2022-01-25 3:39 UTC (permalink / raw)
To: linux-kernel
Cc: Pingfan Liu, Eric Biederman, Peter Zijlstra, Thomas Gleixner,
Valentin Schneider, Vincent Donnefort, Ingo Molnar, Mark Rutland,
YueHaibing, Baokun Li, Randy Dunlap, kexec
The following identical code piece appears in both
migrate_to_reboot_cpu() and smp_shutdown_nonboot_cpus():
if (!cpu_online(primary_cpu))
primary_cpu = cpumask_first(cpu_online_mask);
Although the kexec-reboot task can get through a cpu_down() on its cpu,
this code looks a little confusing.
Make things straight forward by keep cpu hotplug disabled until
smp_shutdown_nonboot_cpus() holds cpu_add_remove_lock. By this way, the
rebooting cpu can keep unchanged.
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Vincent Donnefort <vincent.donnefort@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Baokun Li <libaokun1@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: kexec@lists.infradead.org
To: linux-kernel@vger.kernel.org
---
kernel/cpu.c | 16 ++++++++++------
kernel/kexec_core.c | 10 ++++------
2 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 407a2568f35e..bc687d59ca90 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1227,20 +1227,24 @@ int remove_cpu(unsigned int cpu)
}
EXPORT_SYMBOL_GPL(remove_cpu);
+/* primary_cpu keeps unchanged after migrate_to_reboot_cpu() */
void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
{
unsigned int cpu;
int error;
+ /*
+ * Block other cpu hotplug event, so primary_cpu is always online if
+ * it is not touched by us
+ */
cpu_maps_update_begin();
-
/*
- * Make certain the cpu I'm about to reboot on is online.
- *
- * This is inline to what migrate_to_reboot_cpu() already do.
+ * migrate_to_reboot_cpu() disables CPU hotplug assuming that
+ * no further code needs to use CPU hotplug (which is true in
+ * the reboot case). However, the kexec path depends on using
+ * CPU hotplug again; so re-enable it here.
*/
- if (!cpu_online(primary_cpu))
- primary_cpu = cpumask_first(cpu_online_mask);
+ __cpu_hotplug_enable();
for_each_online_cpu(cpu) {
if (cpu == primary_cpu)
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 68480f731192..db4fa6b174e3 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1168,14 +1168,12 @@ int kernel_kexec(void)
kexec_in_progress = true;
kernel_restart_prepare("kexec reboot");
migrate_to_reboot_cpu();
-
/*
- * migrate_to_reboot_cpu() disables CPU hotplug assuming that
- * no further code needs to use CPU hotplug (which is true in
- * the reboot case). However, the kexec path depends on using
- * CPU hotplug again; so re-enable it here.
+ * migrate_to_reboot_cpu() disables CPU hotplug. If an arch
+ * relies on the cpu teardown to achieve reboot, it needs to
+ * re-enable CPU hotplug there.
*/
- cpu_hotplug_enable();
+
pr_notice("Starting new kernel\n");
machine_shutdown();
}
--
2.31.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable
2022-01-25 3:39 [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable Pingfan Liu
@ 2022-01-25 16:29 ` Valentin Schneider
2022-01-26 2:45 ` Pingfan Liu
0 siblings, 1 reply; 5+ messages in thread
From: Valentin Schneider @ 2022-01-25 16:29 UTC (permalink / raw)
To: Pingfan Liu, linux-kernel
Cc: Pingfan Liu, Eric Biederman, Peter Zijlstra, Thomas Gleixner,
Vincent Donnefort, Ingo Molnar, Mark Rutland, YueHaibing,
Baokun Li, Randy Dunlap, kexec
On 25/01/22 11:39, Pingfan Liu wrote:
> The following identical code piece appears in both
> migrate_to_reboot_cpu() and smp_shutdown_nonboot_cpus():
>
> if (!cpu_online(primary_cpu))
> primary_cpu = cpumask_first(cpu_online_mask);
>
> Although the kexec-reboot task can get through a cpu_down() on its cpu,
> this code looks a little confusing.
>
> Make things straight forward by keep cpu hotplug disabled until
> smp_shutdown_nonboot_cpus() holds cpu_add_remove_lock. By this way, the
> rebooting cpu can keep unchanged.
>
So is this supposed to be a refactor with no change in behaviour? AFAICT it
actually does change things (and isn't necessarily clearer).
> Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
> Cc: Eric Biederman <ebiederm@xmission.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Valentin Schneider <valentin.schneider@arm.com>
> Cc: Vincent Donnefort <vincent.donnefort@arm.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: YueHaibing <yuehaibing@huawei.com>
> Cc: Baokun Li <libaokun1@huawei.com>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Cc: kexec@lists.infradead.org
> To: linux-kernel@vger.kernel.org
> ---
> kernel/cpu.c | 16 ++++++++++------
> kernel/kexec_core.c | 10 ++++------
> 2 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/kernel/cpu.c b/kernel/cpu.c
> index 407a2568f35e..bc687d59ca90 100644
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -1227,20 +1227,24 @@ int remove_cpu(unsigned int cpu)
> }
> EXPORT_SYMBOL_GPL(remove_cpu);
>
> +/* primary_cpu keeps unchanged after migrate_to_reboot_cpu() */
> void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
> {
> unsigned int cpu;
> int error;
>
> + /*
> + * Block other cpu hotplug event, so primary_cpu is always online if
> + * it is not touched by us
> + */
> cpu_maps_update_begin();
> -
> /*
> - * Make certain the cpu I'm about to reboot on is online.
> - *
> - * This is inline to what migrate_to_reboot_cpu() already do.
> + * migrate_to_reboot_cpu() disables CPU hotplug assuming that
> + * no further code needs to use CPU hotplug (which is true in
> + * the reboot case). However, the kexec path depends on using
> + * CPU hotplug again; so re-enable it here.
> */
> - if (!cpu_online(primary_cpu))
> - primary_cpu = cpumask_first(cpu_online_mask);
> + __cpu_hotplug_enable();
>
> for_each_online_cpu(cpu) {
> if (cpu == primary_cpu)
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index 68480f731192..db4fa6b174e3 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -1168,14 +1168,12 @@ int kernel_kexec(void)
> kexec_in_progress = true;
> kernel_restart_prepare("kexec reboot");
> migrate_to_reboot_cpu();
> -
> /*
> - * migrate_to_reboot_cpu() disables CPU hotplug assuming that
> - * no further code needs to use CPU hotplug (which is true in
> - * the reboot case). However, the kexec path depends on using
> - * CPU hotplug again; so re-enable it here.
> + * migrate_to_reboot_cpu() disables CPU hotplug. If an arch
> + * relies on the cpu teardown to achieve reboot, it needs to
> + * re-enable CPU hotplug there.
> */
> - cpu_hotplug_enable();
> +
Not all archs map machine_shutdown() to smp_shutdown_nonboot_cpus(), other
archs will now be missing a cpu_hotplug_enable() prior to a kexec
machine_shutdown(). That said, AFAICT none of those archs rely on the
hotplug machinery in machine_shutdown(), so it might be OK, but that's not
obvious at all.
> pr_notice("Starting new kernel\n");
> machine_shutdown();
> }
> --
> 2.31.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable
2022-01-25 16:29 ` Valentin Schneider
@ 2022-01-26 2:45 ` Pingfan Liu
2022-01-26 15:06 ` Valentin Schneider
0 siblings, 1 reply; 5+ messages in thread
From: Pingfan Liu @ 2022-01-26 2:45 UTC (permalink / raw)
To: Valentin Schneider
Cc: LKML, Eric Biederman, Peter Zijlstra, Thomas Gleixner,
Vincent Donnefort, Ingo Molnar, Mark Rutland, YueHaibing,
Baokun Li, Randy Dunlap, Kexec Mailing List
On Wed, Jan 26, 2022 at 12:29 AM Valentin Schneider
<valentin.schneider@arm.com> wrote:
>
> On 25/01/22 11:39, Pingfan Liu wrote:
> > The following identical code piece appears in both
> > migrate_to_reboot_cpu() and smp_shutdown_nonboot_cpus():
> >
> > if (!cpu_online(primary_cpu))
> > primary_cpu = cpumask_first(cpu_online_mask);
> >
> > Although the kexec-reboot task can get through a cpu_down() on its cpu,
> > this code looks a little confusing.
> >
> > Make things straight forward by keep cpu hotplug disabled until
> > smp_shutdown_nonboot_cpus() holds cpu_add_remove_lock. By this way, the
> > rebooting cpu can keep unchanged.
> >
>
> So is this supposed to be a refactor with no change in behaviour? AFAICT it
> actually does change things (and isn't necessarily clearer).
>
Yes, as you have seen, it does change behavior. Before this patch,
there is a breakage:
migrate_to_reboot_cpu();
cpu_hotplug_enable();
----------> technical, here can
comes a cpu_down(this_cpu)
machine_shutdown();
And this patch squeezes out this breakage.
> > Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
> > Cc: Eric Biederman <ebiederm@xmission.com>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Valentin Schneider <valentin.schneider@arm.com>
> > Cc: Vincent Donnefort <vincent.donnefort@arm.com>
> > Cc: Ingo Molnar <mingo@kernel.org>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: YueHaibing <yuehaibing@huawei.com>
> > Cc: Baokun Li <libaokun1@huawei.com>
> > Cc: Randy Dunlap <rdunlap@infradead.org>
> > Cc: kexec@lists.infradead.org
> > To: linux-kernel@vger.kernel.org
> > ---
> > kernel/cpu.c | 16 ++++++++++------
> > kernel/kexec_core.c | 10 ++++------
> > 2 files changed, 14 insertions(+), 12 deletions(-)
> >
> > diff --git a/kernel/cpu.c b/kernel/cpu.c
> > index 407a2568f35e..bc687d59ca90 100644
> > --- a/kernel/cpu.c
> > +++ b/kernel/cpu.c
> > @@ -1227,20 +1227,24 @@ int remove_cpu(unsigned int cpu)
> > }
> > EXPORT_SYMBOL_GPL(remove_cpu);
> >
> > +/* primary_cpu keeps unchanged after migrate_to_reboot_cpu() */
> > void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
> > {
> > unsigned int cpu;
> > int error;
> >
> > + /*
> > + * Block other cpu hotplug event, so primary_cpu is always online if
> > + * it is not touched by us
> > + */
> > cpu_maps_update_begin();
> > -
> > /*
> > - * Make certain the cpu I'm about to reboot on is online.
> > - *
> > - * This is inline to what migrate_to_reboot_cpu() already do.
> > + * migrate_to_reboot_cpu() disables CPU hotplug assuming that
> > + * no further code needs to use CPU hotplug (which is true in
> > + * the reboot case). However, the kexec path depends on using
> > + * CPU hotplug again; so re-enable it here.
> > */
> > - if (!cpu_online(primary_cpu))
> > - primary_cpu = cpumask_first(cpu_online_mask);
> > + __cpu_hotplug_enable();
> >
> > for_each_online_cpu(cpu) {
> > if (cpu == primary_cpu)
> > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> > index 68480f731192..db4fa6b174e3 100644
> > --- a/kernel/kexec_core.c
> > +++ b/kernel/kexec_core.c
> > @@ -1168,14 +1168,12 @@ int kernel_kexec(void)
> > kexec_in_progress = true;
> > kernel_restart_prepare("kexec reboot");
> > migrate_to_reboot_cpu();
> > -
> > /*
> > - * migrate_to_reboot_cpu() disables CPU hotplug assuming that
> > - * no further code needs to use CPU hotplug (which is true in
> > - * the reboot case). However, the kexec path depends on using
> > - * CPU hotplug again; so re-enable it here.
> > + * migrate_to_reboot_cpu() disables CPU hotplug. If an arch
> > + * relies on the cpu teardown to achieve reboot, it needs to
> > + * re-enable CPU hotplug there.
> > */
> > - cpu_hotplug_enable();
> > +
>
> Not all archs map machine_shutdown() to smp_shutdown_nonboot_cpus(), other
> archs will now be missing a cpu_hotplug_enable() prior to a kexec
> machine_shutdown(). That said, AFAICT none of those archs rely on the
> hotplug machinery in machine_shutdown(), so it might be OK, but that's not
> obvious at all.
>
At the first glance, it may be not obvious, but tracing down
cpu_hotplug_enable() to the variable cpu_hotplug_disabled, you can
find out the limited involved functions are all related to
cpu_up/cpu_down.
IOW, if no code path connects with the interface of cpu_up/cpu_down,
then kexec-reboot will not be affected.
And after this patch, it is more clear how to handle the following cases:
arch/arm/kernel/reboot.c:94: smp_shutdown_nonboot_cpus(reboot_cpu);
arch/arm64/kernel/process.c:88: smp_shutdown_nonboot_cpus(reboot_cpu);
arch/ia64/kernel/process.c:578: smp_shutdown_nonboot_cpus(reboot_cpu);
Thanks,
Pingfan
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable
2022-01-26 2:45 ` Pingfan Liu
@ 2022-01-26 15:06 ` Valentin Schneider
2022-01-27 8:44 ` Pingfan Liu
0 siblings, 1 reply; 5+ messages in thread
From: Valentin Schneider @ 2022-01-26 15:06 UTC (permalink / raw)
To: Pingfan Liu
Cc: LKML, Eric Biederman, Peter Zijlstra, Thomas Gleixner,
Vincent Donnefort, Ingo Molnar, Mark Rutland, YueHaibing,
Baokun Li, Randy Dunlap, Kexec Mailing List
On 26/01/22 10:45, Pingfan Liu wrote:
> On Wed, Jan 26, 2022 at 12:29 AM Valentin Schneider
> <valentin.schneider@arm.com> wrote:
>>
>> On 25/01/22 11:39, Pingfan Liu wrote:
>> > The following identical code piece appears in both
>> > migrate_to_reboot_cpu() and smp_shutdown_nonboot_cpus():
>> >
>> > if (!cpu_online(primary_cpu))
>> > primary_cpu = cpumask_first(cpu_online_mask);
>> >
>> > Although the kexec-reboot task can get through a cpu_down() on its cpu,
>> > this code looks a little confusing.
>> >
>> > Make things straight forward by keep cpu hotplug disabled until
>> > smp_shutdown_nonboot_cpus() holds cpu_add_remove_lock. By this way, the
>> > rebooting cpu can keep unchanged.
>> >
>>
>> So is this supposed to be a refactor with no change in behaviour? AFAICT it
>> actually does change things (and isn't necessarily clearer).
>>
> Yes, as you have seen, it does change behavior. Before this patch,
> there is a breakage:
> migrate_to_reboot_cpu();
> cpu_hotplug_enable();
> ----------> technical, here can
> comes a cpu_down(this_cpu)
> machine_shutdown();
>
> And this patch squeezes out this breakage.
>
Ok, that's worth pointing out in the changelog.
>> > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
>> > index 68480f731192..db4fa6b174e3 100644
>> > --- a/kernel/kexec_core.c
>> > +++ b/kernel/kexec_core.c
>> > @@ -1168,14 +1168,12 @@ int kernel_kexec(void)
>> > kexec_in_progress = true;
>> > kernel_restart_prepare("kexec reboot");
>> > migrate_to_reboot_cpu();
>> > -
>> > /*
>> > - * migrate_to_reboot_cpu() disables CPU hotplug assuming that
>> > - * no further code needs to use CPU hotplug (which is true in
>> > - * the reboot case). However, the kexec path depends on using
>> > - * CPU hotplug again; so re-enable it here.
>> > + * migrate_to_reboot_cpu() disables CPU hotplug. If an arch
>> > + * relies on the cpu teardown to achieve reboot, it needs to
>> > + * re-enable CPU hotplug there.
>> > */
>> > - cpu_hotplug_enable();
>> > +
>>
>> Not all archs map machine_shutdown() to smp_shutdown_nonboot_cpus(), other
>> archs will now be missing a cpu_hotplug_enable() prior to a kexec
>> machine_shutdown(). That said, AFAICT none of those archs rely on the
>> hotplug machinery in machine_shutdown(), so it might be OK, but that's not
>> obvious at all.
>>
> At the first glance, it may be not obvious, but tracing down
> cpu_hotplug_enable() to the variable cpu_hotplug_disabled, you can
> find out the limited involved functions are all related to
> cpu_up/cpu_down.
>
> IOW, if no code path connects with the interface of cpu_up/cpu_down,
> then kexec-reboot will not be affected.
>
That's my point, this only works if the other archs truly do not rely on
hotplug for machine_shutdown(), which seems to be the case but it wouldn't
hurt for you to double-check that and explicitely call it out in the
changelog.
> And after this patch, it is more clear how to handle the following cases:
> arch/arm/kernel/reboot.c:94: smp_shutdown_nonboot_cpus(reboot_cpu);
> arch/arm64/kernel/process.c:88: smp_shutdown_nonboot_cpus(reboot_cpu);
> arch/ia64/kernel/process.c:578: smp_shutdown_nonboot_cpus(reboot_cpu);
>
FWIW riscv is also concerned.
> Thanks,
> Pingfan
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable
2022-01-26 15:06 ` Valentin Schneider
@ 2022-01-27 8:44 ` Pingfan Liu
0 siblings, 0 replies; 5+ messages in thread
From: Pingfan Liu @ 2022-01-27 8:44 UTC (permalink / raw)
To: Valentin Schneider
Cc: LKML, Eric Biederman, Peter Zijlstra, Thomas Gleixner,
Vincent Donnefort, Ingo Molnar, Mark Rutland, YueHaibing,
Baokun Li, Randy Dunlap, Kexec Mailing List
On Wed, Jan 26, 2022 at 11:06 PM Valentin Schneider
<valentin.schneider@arm.com> wrote:
>
> On 26/01/22 10:45, Pingfan Liu wrote:
> > On Wed, Jan 26, 2022 at 12:29 AM Valentin Schneider
> > <valentin.schneider@arm.com> wrote:
> >>
> >> On 25/01/22 11:39, Pingfan Liu wrote:
> >> > The following identical code piece appears in both
> >> > migrate_to_reboot_cpu() and smp_shutdown_nonboot_cpus():
> >> >
> >> > if (!cpu_online(primary_cpu))
> >> > primary_cpu = cpumask_first(cpu_online_mask);
> >> >
> >> > Although the kexec-reboot task can get through a cpu_down() on its cpu,
> >> > this code looks a little confusing.
> >> >
> >> > Make things straight forward by keep cpu hotplug disabled until
> >> > smp_shutdown_nonboot_cpus() holds cpu_add_remove_lock. By this way, the
> >> > rebooting cpu can keep unchanged.
> >> >
> >>
> >> So is this supposed to be a refactor with no change in behaviour? AFAICT it
> >> actually does change things (and isn't necessarily clearer).
> >>
> > Yes, as you have seen, it does change behavior. Before this patch,
> > there is a breakage:
> > migrate_to_reboot_cpu();
> > cpu_hotplug_enable();
> > ----------> technical, here can
> > comes a cpu_down(this_cpu)
> > machine_shutdown();
> >
> > And this patch squeezes out this breakage.
> >
>
> Ok, that's worth pointing out in the changelog.
>
Sure, I will update it.
> >> > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> >> > index 68480f731192..db4fa6b174e3 100644
> >> > --- a/kernel/kexec_core.c
> >> > +++ b/kernel/kexec_core.c
> >> > @@ -1168,14 +1168,12 @@ int kernel_kexec(void)
> >> > kexec_in_progress = true;
> >> > kernel_restart_prepare("kexec reboot");
> >> > migrate_to_reboot_cpu();
> >> > -
> >> > /*
> >> > - * migrate_to_reboot_cpu() disables CPU hotplug assuming that
> >> > - * no further code needs to use CPU hotplug (which is true in
> >> > - * the reboot case). However, the kexec path depends on using
> >> > - * CPU hotplug again; so re-enable it here.
> >> > + * migrate_to_reboot_cpu() disables CPU hotplug. If an arch
> >> > + * relies on the cpu teardown to achieve reboot, it needs to
> >> > + * re-enable CPU hotplug there.
> >> > */
> >> > - cpu_hotplug_enable();
> >> > +
> >>
> >> Not all archs map machine_shutdown() to smp_shutdown_nonboot_cpus(), other
> >> archs will now be missing a cpu_hotplug_enable() prior to a kexec
> >> machine_shutdown(). That said, AFAICT none of those archs rely on the
> >> hotplug machinery in machine_shutdown(), so it might be OK, but that's not
> >> obvious at all.
> >>
> > At the first glance, it may be not obvious, but tracing down
> > cpu_hotplug_enable() to the variable cpu_hotplug_disabled, you can
> > find out the limited involved functions are all related to
> > cpu_up/cpu_down.
> >
> > IOW, if no code path connects with the interface of cpu_up/cpu_down,
> > then kexec-reboot will not be affected.
> >
>
> That's my point, this only works if the other archs truly do not rely on
> hotplug for machine_shutdown(), which seems to be the case but it wouldn't
> hurt for you to double-check that and explicitely call it out in the
> changelog.
>
OK, I will update the change log. BTW, besides x86, I have just
finished the test on powerpc, both of them works fine with this patch
> > And after this patch, it is more clear how to handle the following cases:
> > arch/arm/kernel/reboot.c:94: smp_shutdown_nonboot_cpus(reboot_cpu);
> > arch/arm64/kernel/process.c:88: smp_shutdown_nonboot_cpus(reboot_cpu);
> > arch/ia64/kernel/process.c:578: smp_shutdown_nonboot_cpus(reboot_cpu);
> >
>
> FWIW riscv is also concerned.
I think its current statement is right.
arch/riscv/kernel/machine_kexec.c:135:
smp_shutdown_nonboot_cpus(smp_processor_id());
Thanks,
Pingfan
>
> > Thanks,
> > Pingfan
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-01-27 8:44 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-01-25 3:39 [PATCH] kexec: disable cpu hotplug until the rebooting cpu is stable Pingfan Liu
2022-01-25 16:29 ` Valentin Schneider
2022-01-26 2:45 ` Pingfan Liu
2022-01-26 15:06 ` Valentin Schneider
2022-01-27 8:44 ` Pingfan Liu
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