If I boot with: maxcpus=2 possible_cpus=4, I get
# grep . /sys/devices/system/cpu/cpu[0-9]*/online'
/sys/devices/system/cpu/cpu1/online:1
/sys/devices/system/cpu/cpu2/online:1
/sys/devices/system/cpu/cpu3/online:1
on bad kernels, and this on working ones:
/sys/devices/system/cpu/cpu1/online:1
/sys/devices/system/cpu/cpu2/online:0
/sys/devices/system/cpu/cpu3/online:0
I also get -EINVAL if I try to re-offline them in this state. 2 and 3
don't show up in /proc/cpuinfo, so sysfs just looks broken here. This
happens in a KVM guest, so it should be dirt-simple for anyone to reproduce.
I bisected it down to:
> commit 0902a9044fa5b7a0456ea4daacec2c2b3189ba8c
> Author: Rafael J. Wysocki <[email protected]>
> Date: Fri May 3 00:25:49 2013 +0200
>
> Driver core: Use generic offline/online for CPU offline/online
>
> Rework the CPU hotplug code in drivers/base/cpu.c to use the
> generic offline/online support introduced previously instead of
> its own CPU-specific code.
>
> For this purpose, modify cpu_subsys to provide offline and online
> callbacks for CONFIG_HOTPLUG_CPU set and remove the code handling
> the CPU-specific 'online' sysfs attribute.
>
> This modification is not supposed to change the user-observable
> behavior of the kernel (i.e. the 'online' attribute will be present
> in exactly the same place in sysfs and should trigger exactly the
> same actions as before).
>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> Acked-by: Greg Kroah-Hartman <[email protected]>
> Reviewed-by: Toshi Kani <[email protected]>
On Wed, 2013-05-29 at 10:10 -0700, Dave Hansen wrote:
> If I boot with: maxcpus=2 possible_cpus=4, I get
>
> # grep . /sys/devices/system/cpu/cpu[0-9]*/online'
> /sys/devices/system/cpu/cpu1/online:1
> /sys/devices/system/cpu/cpu2/online:1
> /sys/devices/system/cpu/cpu3/online:1
>
> on bad kernels, and this on working ones:
>
> /sys/devices/system/cpu/cpu1/online:1
> /sys/devices/system/cpu/cpu2/online:0
> /sys/devices/system/cpu/cpu3/online:0
>
>
> I also get -EINVAL if I try to re-offline them in this state. 2 and 3
> don't show up in /proc/cpuinfo, so sysfs just looks broken here. This
> happens in a KVM guest, so it should be dirt-simple for anyone to reproduce.
>
> I bisected it down to:
>
> > commit 0902a9044fa5b7a0456ea4daacec2c2b3189ba8c
> > Author: Rafael J. Wysocki <[email protected]>
> > Date: Fri May 3 00:25:49 2013 +0200
> >
> > Driver core: Use generic offline/online for CPU offline/online
> >
> > Rework the CPU hotplug code in drivers/base/cpu.c to use the
> > generic offline/online support introduced previously instead of
> > its own CPU-specific code.
> >
> > For this purpose, modify cpu_subsys to provide offline and online
> > callbacks for CONFIG_HOTPLUG_CPU set and remove the code handling
> > the CPU-specific 'online' sysfs attribute.
> >
> > This modification is not supposed to change the user-observable
> > behavior of the kernel (i.e. the 'online' attribute will be present
> > in exactly the same place in sysfs and should trigger exactly the
> > same actions as before).
> >
> > Signed-off-by: Rafael J. Wysocki <[email protected]>
> > Acked-by: Greg Kroah-Hartman <[email protected]>
> > Reviewed-by: Toshi Kani <[email protected]>
Thanks for the report. The following patch fixes the problem.
-Toshi
====
From: Toshi Kani <[email protected]>
Subject: [PATCH] ACPI: Fix sysfs cpu/online of offlined cpus
As reported by Dave Hansen, sysfs cpu/online shows 1 for
offlined cpus at boot.
https://lkml.org/lkml/2013/5/29/403
Fix this problem by initializing dev.offline with cpu_online()
when registering a cpu.
Reported-by: Dave Hansen <[email protected]>
Signed-off-by: Toshi Kani <[email protected]>
---
drivers/base/cpu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 130ba0b..b9f0eec 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -281,6 +281,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
cpu->dev.bus = &cpu_subsys;
cpu->dev.release = cpu_device_release;
cpu->dev.offline_disabled = !cpu->hotpluggable;
+ cpu->dev.offline = !cpu_online(num);
#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
cpu->dev.bus->uevent = arch_cpu_uevent;
#endif
--
1.8.1.4
On Wed, 2013-05-29 at 12:35 -0600, Toshi Kani wrote:
> On Wed, 2013-05-29 at 10:10 -0700, Dave Hansen wrote:
:
> Thanks for the report. The following patch fixes the problem.
> -Toshi
>
> ====
> From: Toshi Kani <[email protected]>
> Subject: [PATCH] ACPI: Fix sysfs cpu/online of offlined cpus
Typo. The subject needs to be:
Subject: [PATCH] cpu: Fix sysfs cpu/online of offlined cpus
-Toshi
> As reported by Dave Hansen, sysfs cpu/online shows 1 for
> offlined cpus at boot.
> https://lkml.org/lkml/2013/5/29/403
>
> Fix this problem by initializing dev.offline with cpu_online()
> when registering a cpu.
>
> Reported-by: Dave Hansen <[email protected]>
> Signed-off-by: Toshi Kani <[email protected]>
> ---
> drivers/base/cpu.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
> index 130ba0b..b9f0eec 100644
> --- a/drivers/base/cpu.c
> +++ b/drivers/base/cpu.c
> @@ -281,6 +281,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
> cpu->dev.bus = &cpu_subsys;
> cpu->dev.release = cpu_device_release;
> cpu->dev.offline_disabled = !cpu->hotpluggable;
> + cpu->dev.offline = !cpu_online(num);
> #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
> cpu->dev.bus->uevent = arch_cpu_uevent;
> #endif
On 5/29/2013 8:50 PM, Toshi Kani wrote:
> On Wed, 2013-05-29 at 12:35 -0600, Toshi Kani wrote:
>> On Wed, 2013-05-29 at 10:10 -0700, Dave Hansen wrote:
> :
>
>> Thanks for the report. The following patch fixes the problem.
>> -Toshi
>>
>> ====
>> From: Toshi Kani <[email protected]>
>> Subject: [PATCH] ACPI: Fix sysfs cpu/online of offlined cpus
> Typo. The subject needs to be:
>
> Subject: [PATCH] cpu: Fix sysfs cpu/online of offlined cpus
>
> -Toshi
>
>> As reported by Dave Hansen, sysfs cpu/online shows 1 for
>> offlined cpus at boot.
>> https://lkml.org/lkml/2013/5/29/403
>>
>> Fix this problem by initializing dev.offline with cpu_online()
>> when registering a cpu.
>>
>> Reported-by: Dave Hansen <[email protected]>
>> Signed-off-by: Toshi Kani <[email protected]>
Thanks Toshi!
Dave, can you please confirm that the problem is fixed by this patch?
Rafael
>> ---
>> drivers/base/cpu.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
>> index 130ba0b..b9f0eec 100644
>> --- a/drivers/base/cpu.c
>> +++ b/drivers/base/cpu.c
>> @@ -281,6 +281,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
>> cpu->dev.bus = &cpu_subsys;
>> cpu->dev.release = cpu_device_release;
>> cpu->dev.offline_disabled = !cpu->hotpluggable;
>> + cpu->dev.offline = !cpu_online(num);
>> #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
>> cpu->dev.bus->uevent = arch_cpu_uevent;
>> #endif
>
---------------------------------------------------------------------
Intel Technology Poland sp. z o.o.
z siedziba w Gdansku
ul. Slowackiego 173
80-298 Gdansk
Sad Rejonowy Gdansk Polnoc w Gdansku,
VII Wydzial Gospodarczy Krajowego Rejestru Sadowego,
numer KRS 101882
NIP 957-07-52-316
Kapital zakladowy 200.000 zl
This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay? ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?
On 05/29/2013 12:02 PM, Rafael J. Wysocki wrote:
>>> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
>>> index 130ba0b..b9f0eec 100644
>>> --- a/drivers/base/cpu.c
>>> +++ b/drivers/base/cpu.c
>>> @@ -281,6 +281,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
>>> cpu->dev.bus = &cpu_subsys;
>>> cpu->dev.release = cpu_device_release;
>>> cpu->dev.offline_disabled = !cpu->hotpluggable;
>>> + cpu->dev.offline = !cpu_online(num);
>>> #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
>>> cpu->dev.bus->uevent = arch_cpu_uevent;
>>> #endif
This gets things working for me again. Thanks for the quick response!
Tested-by: Dave Hansen <[email protected]>
On Wednesday, May 29, 2013 03:14:12 PM Dave Hansen wrote:
> On 05/29/2013 12:02 PM, Rafael J. Wysocki wrote:
> >>> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
> >>> index 130ba0b..b9f0eec 100644
> >>> --- a/drivers/base/cpu.c
> >>> +++ b/drivers/base/cpu.c
> >>> @@ -281,6 +281,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
> >>> cpu->dev.bus = &cpu_subsys;
> >>> cpu->dev.release = cpu_device_release;
> >>> cpu->dev.offline_disabled = !cpu->hotpluggable;
> >>> + cpu->dev.offline = !cpu_online(num);
> >>> #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
> >>> cpu->dev.bus->uevent = arch_cpu_uevent;
> >>> #endif
>
> This gets things working for me again. Thanks for the quick response!
>
> Tested-by: Dave Hansen <[email protected]>
Applied.
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.