Skip to content
Commit a18d098f authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Reapply "x86/smp: Eliminate mwait_play_dead_cpuid_hint()"



Revert commit 70523f33 ("Revert "x86/smp: Eliminate
mwait_play_dead_cpuid_hint()"") to reapply the changes from commit
96040f72 ("x86/smp: Eliminate mwait_play_dead_cpuid_hint()")
reverted by it.

Previously, these changes caused idle power to rise on systems booting
with "nosmt" in the kernel command line because they effectively caused
"dead" SMT siblings to remain in idle state C1 after executing the HLT
instruction, which prevented the processor from reaching package idle
states deeper than PC2 going forward.

Now, the "dead" SMT siblings are rescanned after initializing a proper
cpuidle driver for the processor (either intel_idle or ACPI idle), at
which point they are able to enter a sufficiently deep idle state
in native_play_dead() via cpuidle, so the code changes in question can
be reapplied.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Tested-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/7813065.EvYhyI6sBW@rjwysocki.net
parent f694481b
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment