Re: [PATCH] perf, x86: Widen Haswell OFFCORE mask

From: Stephane Eranian
Date: Mon Jul 14 2014 - 20:41:53 EST


On Sat, Jul 12, 2014 at 2:06 AM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> Haswell supports more bits in the offcore_rsp_* MSRs than Sandy
> Bridge. Previously the Haswell code was using the Sandy Bridge
> extra register definitions, which prevented users from setting
> all of these bits. This in term did not allow to set some valid
> SNOOP_* bits, among others.
>
> I allowed all bits the CPU does not #GP on. This is ok because
> it's protected by a model check.
>
> Add a new extra_regs table for Haswell and use. Except for the
> widened mask it is identical to Sandy Bridge.
>
You're adding an extra_regs[] array which is identical to the one
used by SNB-EP. So why not use that one instead of defining yet
another extra_regs array?


> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> ---
> arch/x86/kernel/cpu/perf_event_intel.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
> index adb02aa..5d41e2b 100644
> --- a/arch/x86/kernel/cpu/perf_event_intel.c
> +++ b/arch/x86/kernel/cpu/perf_event_intel.c
> @@ -189,6 +189,14 @@ static struct extra_reg intel_snbep_extra_regs[] __read_mostly = {
> EVENT_EXTRA_END
> };
>
> +static struct extra_reg intel_hsw_extra_regs[] __read_mostly = {
> + /* must define OFFCORE_RSP_X first, see intel_fixup_er() */
> + INTEL_UEVENT_EXTRA_REG(0x01b7, MSR_OFFCORE_RSP_0, 0x3fffff8fffull, RSP_0),
> + INTEL_UEVENT_EXTRA_REG(0x01bb, MSR_OFFCORE_RSP_1, 0x3fffff8fffull, RSP_1),
> + INTEL_UEVENT_PEBS_LDLAT_EXTRA_REG(0x01cd),
> + EVENT_EXTRA_END
> +};
> +
> EVENT_ATTR_STR(mem-loads, mem_ld_nhm, "event=0x0b,umask=0x10,ldlat=3");
> EVENT_ATTR_STR(mem-loads, mem_ld_snb, "event=0xcd,umask=0x1,ldlat=3");
> EVENT_ATTR_STR(mem-stores, mem_st_snb, "event=0xcd,umask=0x2");
> @@ -2504,7 +2512,7 @@ __init int intel_pmu_init(void)
>
> x86_pmu.event_constraints = intel_hsw_event_constraints;
> x86_pmu.pebs_constraints = intel_hsw_pebs_event_constraints;
> - x86_pmu.extra_regs = intel_snb_extra_regs;
> + x86_pmu.extra_regs = intel_hsw_extra_regs;
> x86_pmu.pebs_aliases = intel_pebs_aliases_snb;
> /* all extra regs are per-cpu when HT is on */
> x86_pmu.er_flags |= ERF_HAS_RSP_1;
> --
> 1.9.3
>
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