Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH 0/2] Protect cpu map updates from ACPI processor | Date | Tue, 13 Aug 2013 02:43:33 +0200 |
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On Monday, August 12, 2013 09:45:52 AM Toshi Kani wrote: > CPU system maps are protected with reader/writer locks. The reader > lock, put_online_cpus(), assures that the maps are not updated while > holding the lock. The writer lock, cpu_hotplug_begin(), is used to > udpate the cpu maps along with cpu_maps_update_begin(). > > However, the ACPI processor handler updates the cpu maps without > holding the the writer lock. This patchset fixes this problem. > > --- > The patchset is based on linux-next of the pm tree.
Basically looks OK to me, but I'd just merge the patches together, because the [2/2] is the very reason for the change made by [1/2].
Also it would be good to mention the actual scenario that may lead to problems with that.
Thanks, Rafael
> --- > Toshi Kani (2): > CPU hotplug: Export cpu_hotplug_begin() interface > ACPI: Acquire writer lock to update cpu maps > > --- > drivers/acpi/acpi_processor.c | 21 ++++++++++++++++----- > include/linux/cpu.h | 2 ++ > kernel/cpu.c | 4 ++-- > 3 files changed, 20 insertions(+), 7 deletions(-) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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