[PATCH 0/1][SRU][J] Improve performance and idle power consumption for AMD CPUs

Alex Hung alex.hung at canonical.com
Thu Jan 6 21:08:36 UTC 2022


  BugLink: https://bugs.launchpad.net/bugs/1941893

[Impact]

  This can improve AMD performance for all Zen or newer CPU which support C3 shares cache.

[Fix]

  Its not necessary to flush the caches in software before entering C3.

  Empirical measurements show:
   40-45% improvement in speedometer score.
   ~15% improvement in idle power.

  The patch is cherry-picked from kernel 5.16

[Test]

  This is requested by AMD.

[Where problems could occur]

  Low risk. This only works on AMD Zen CPUs that supports this features. AMD
  tested it and provided estimated measurement results.

Deepak Sharma (1):
  x86: ACPI: cstate: Optimize C3 entry on AMD CPUs

 arch/x86/kernel/acpi/cstate.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

-- 
2.32.0




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