Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: powerpc/powernv: Clear LPCR[PECE1] via stop-api only for deep state offline | Date | Thu, 21 Sep 2017 11:46:43 +1000 (AEST) |
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On Thu, 2017-08-31 at 11:47:41 UTC, "Gautham R. Shenoy" wrote: > From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> > > commit 24be85a23d1f ("powerpc/powernv: Clear PECE1 in LPCR via > stop-api only on Hotplug") clears the PECE1 bit of the LPCR via > stop-api during CPU-Hotplug to prevent wakeup due to a decrementer on > an offlined CPU which is in a deep stop state. > > In the case where the stop-api support is found to be lacking, the > commit 785a12afdb4a ("powerpc/powernv/idle: Disable LOSE_FULL_CONTEXT > states when stop-api fails") disables deep states that lose hypervisor > context. Thus in this case, the offlined CPU will be put to some > shallow idle state. > > However, we currently unconditionally clear the PECE1 in LPCR via > stop-api during CPU-Hotplug even when deep states are disabled due to > stop-api failure. > > Fix this by clearing PECE1 of LPCR via stop-api during CPU-Hotplug > *only* when the offlined CPU will be put to a deep state that loses > hypervisor context. > > Fixes: commit 24be85a23d1f ("powerpc/powernv: Clear PECE1 in LPCR via > stop-api only on Hotplug") > > Reported-by: Pavithra Prakash <pavirampu@linux.vnet.ibm.com> > Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> > Reviewed-by: Nicholas Piggin <npiggin@gmail.com> > Tested-by: Pavithra Prakash <pavrampu@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/5d298baa41883fc421acfd932799c0
cheers
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