perf/x86/intel/uncore: Implement lazy setup for MSR/MMIO PMUs

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MSR and MMIO uncore PMUs are currently registered at module init time
and appear in sysfs even when no PMU boxes are functional.

Apply the same lazy registration model used by PCI uncore PMUs: the
PMU is registered when the first box is successfully initialized, and
unregistered when the last box exits.  If a box fails to initialize on
a subsequent die, the PMU is marked broken but remains registered to
avoid disrupting any in-flight perf events.

Box allocation and freeing remain at module init/exit time to avoid
repeated kfree/alloc cycles across CPU offline/online events.

Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://patch.msgid.link/20260611160033.66760-9-zide.chen@intel.com

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Zide Chen 2026-06-11 09:00:33 -07:00 • committed by Peter Zijlstra

parent 174f0582e3

commit b25813b179

2 changed files with 22 additions and 62 deletions

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78

arch/x86/events/intel/uncore.c

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6

arch/x86/events/intel/uncore.h

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