• Imre Palik's avatar
    perf/x86/intel: Honour the CPUID for number of fixed counters in hypervisors · f92b7604
    Imre Palik authored
    perf doesn't seem to honour the number of fixed counters specified by CPUID
    leaf 0xa. It always assumes that Intel CPUs have at least 3 fixed counters.
    So if some of the fixed counters are masked out by the hypervisor, it still
    tries to check/set them.
    This patch makes perf behave nicer when the kernel is running under a
    hypervisor that doesn't expose all the counters.
    This patch contains some ideas from Matt Wilson.
    Signed-off-by: default avatarImre Palik <imrep@amazon.de>
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
    Cc: Alexander Kozyrev <alexander.kozyrev@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Artyom Kuanbekov <artyom.kuanbekov@intel.com>
    Cc: David Carrillo-Cisneros <davidcc@google.com>
    Cc: David Woodhouse <dwmw@amazon.co.uk>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: Kan Liang <kan.liang@intel.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Matt Wilson <msw@amazon.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Stephane Eranian <eranian@google.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Link: http://lkml.kernel.org/r/1477037939-15605-1-git-send-email-imrep.amz@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
core.c 115 KB