Messages in this thread | | | Date | Mon, 10 Dec 2018 21:49:15 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/resctrl: Ensure usage of CPUs are locked while needed |
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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@intel.com> > Cc: stable@vger.kernel.org > --- > 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.
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