Commit dff5da6d authored Jun 12, 2009 by Yong Wang Committed by Ingo Molnar Jun 12, 2009

perf_counter/x86: Add a quirk for Atom processors



The fixed-function performance counters do not work on current Atom
processors. Use the general-purpose ones instead.

Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <20090612080855.GA2286@ywang-moblin2.bj.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent faafec1e

arch/x86/kernel/cpu/perf_counter.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -968,6 +968,13 @@ fixed_mode_idx(struct perf_counter counter, struct hw_perf_counter hwc)
		if (!x86_pmu.num_counters_fixed)
		return -1;

		/*
		* Quirk, IA32_FIXED_CTRs do not work on current Atom processors:
		*/
		if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
		boot_cpu_data.x86_model == 28)
		return -1;

		event = hwc->config & ARCH_PERFMON_EVENT_MASK;

		if (unlikely(event == x86_pmu.event_map(PERF_COUNT_HW_INSTRUCTIONS)))