On Wed, Nov 28, 2018 at 10:22:07AM -0800, Reinette Chatre wrote:
> The user triggers the creation of a pseudo-locked region when writing
> the requested schemata to the schemata resctrl file. The pseudo-locking
> of a region is required to be done on a CPU that is associated with the
> cache on which the pseudo-locked region will reside. In order to run the
> locking code on a specific CPU the needed CPU has to be selected and
> ensured to remain online during the entire locking sequence.
>
> At this time the cpu_hotplug_lock is not taken during the pseudo-lock
> region creation and it is thus possible for a CPU to be selected to run
> the pseudo-locking code and then that CPU to go offline before the
> thread is able to run on it.
>
> Fix this by ensuring that the cpu_hotplug_lock is taken while the CPU on
> which code has to run needs to be controlled. Since the cpu_hotplug_lock
> is always taken before rdtgroup_mutex the lock order is maintained.
>
> Fixes: e0bdfe8e36f3 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 4 ++++
> 1 file changed, 4 insertions(+)
This looks like it wants to go in now, right?
If so, pls redo this patch against tip/x86/urgent which has the old
filenames, before the resctrl rename and reorg.
Thx.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
