public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: kan.liang@linux.intel.com
Cc: acme@kernel.org, mingo@kernel.org, linux-kernel@vger.kernel.org,
	eranian@google.com, namhyung@kernel.org, jolsa@redhat.com,
	ak@linux.intel.com, yao.jin@linux.intel.com
Subject: Re: [PATCH 04/12] perf/x86/intel: Support CPUID 10.ECX to disable fixed counters
Date: Tue, 26 Jan 2021 16:53:15 +0100	[thread overview]
Message-ID: <YBA662724snCMudn@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1611088711-17177-5-git-send-email-kan.liang@linux.intel.com>

On Tue, Jan 19, 2021 at 12:38:23PM -0800, kan.liang@linux.intel.com wrote:
> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index a54d4a9..21267dc 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c
> @@ -5206,7 +5209,7 @@ __init int intel_pmu_init(void)
>  	union cpuid10_eax eax;
>  	union cpuid10_ebx ebx;
>  	struct event_constraint *c;
> -	unsigned int unused;
> +	unsigned int fixed_mask;
>  	struct extra_reg *er;
>  	bool pmem = false;
>  	int version, i;
> @@ -5228,7 +5231,7 @@ __init int intel_pmu_init(void)
>  	 * Check whether the Architectural PerfMon supports
>  	 * Branch Misses Retired hw_event or not.
>  	 */
> -	cpuid(10, &eax.full, &ebx.full, &unused, &edx.full);
> +	cpuid(10, &eax.full, &ebx.full, &fixed_mask, &edx.full);
>  	if (eax.split.mask_length < ARCH_PERFMON_EVENTS_COUNT)
>  		return -ENODEV;
>  
> @@ -5255,8 +5258,16 @@ __init int intel_pmu_init(void)
>  	if (version > 1) {
>  		int assume = 3 * !boot_cpu_has(X86_FEATURE_HYPERVISOR);
>  
> -		x86_pmu.num_counters_fixed =
> -			max((int)edx.split.num_counters_fixed, assume);
> +		if (!fixed_mask) {
> +			x86_pmu.num_counters_fixed =
> +				max((int)edx.split.num_counters_fixed, assume);
> +		} else {
> +			/*
> +			 * The fixed-purpose counters are enumerated in the ECX
> +			 * since V5 perfmon.
> +			 */
> +			x86_pmu.num_counters_fixed = fls(fixed_mask);
> +		}
>  	}
>  
>  	if (version >= 4)
> @@ -5847,8 +5858,11 @@ __init int intel_pmu_init(void)
>  		x86_pmu.num_counters_fixed = INTEL_PMC_MAX_FIXED;
>  	}
>  
> -	x86_pmu.intel_ctrl |=
> -		((1LL << x86_pmu.num_counters_fixed)-1) << INTEL_PMC_IDX_FIXED;
> +	if (!fixed_mask) {
> +		x86_pmu.intel_ctrl |=
> +			((1LL << x86_pmu.num_counters_fixed)-1) << INTEL_PMC_IDX_FIXED;
> +	} else
> +		x86_pmu.intel_ctrl |= (u64)fixed_mask << INTEL_PMC_IDX_FIXED;
>  
>  	/* AnyThread may be deprecated on arch perfmon v5 or later */
>  	if (x86_pmu.intel_cap.anythread_deprecated)

Maybe like so.

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index fe940082d49a..274d75d33c14 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4766,7 +4766,7 @@ __init int intel_pmu_init(void)
 	union cpuid10_eax eax;
 	union cpuid10_ebx ebx;
 	struct event_constraint *c;
-	unsigned int unused;
+	unsigned int fixed_mask;
 	struct extra_reg *er;
 	bool pmem = false;
 	int version, i;
@@ -4788,7 +4788,7 @@ __init int intel_pmu_init(void)
 	 * Check whether the Architectural PerfMon supports
 	 * Branch Misses Retired hw_event or not.
 	 */
-	cpuid(10, &eax.full, &ebx.full, &unused, &edx.full);
+	cpuid(10, &eax.full, &ebx.full, &fixed_mask, &edx.full);
 	if (eax.split.mask_length < ARCH_PERFMON_EVENTS_COUNT)
 		return -ENODEV;
 
@@ -4812,11 +4812,18 @@ __init int intel_pmu_init(void)
 	 * Quirk: v2 perfmon does not report fixed-purpose events, so
 	 * assume at least 3 events, when not running in a hypervisor:
 	 */
-	if (version > 1) {
+	if (version > 1 && version < 5) {
 		int assume = 3 * !boot_cpu_has(X86_FEATURE_HYPERVISOR);
 
 		x86_pmu.num_counters_fixed =
 			max((int)edx.split.num_counters_fixed, assume);
+
+		fixed_mask = (1L << x86_pmu.num_counters_fixed) - 1;
+
+	} else if (version >= 5 ) {
+
+		x86_pmu.num_counters_fixed = fls(fixed_mask);
+
 	}
 
 	if (boot_cpu_has(X86_FEATURE_PDCM)) {
@@ -5366,8 +5373,7 @@ __init int intel_pmu_init(void)
 		x86_pmu.num_counters_fixed = INTEL_PMC_MAX_FIXED;
 	}
 
-	x86_pmu.intel_ctrl |=
-		((1LL << x86_pmu.num_counters_fixed)-1) << INTEL_PMC_IDX_FIXED;
+	x86_pmu.intel_ctrl |= (u64)fixed_mask << INTEL_PMC_IDX_FIXED;
 
 	/* AnyThread may be deprecated on arch perfmon v5 or later */
 	if (x86_pmu.intel_cap.anythread_deprecated)

  parent reply	other threads:[~2021-01-26 15:56 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-19 20:38 [PATCH 00/12] perf core PMU support for Sapphire Rapids kan.liang
2021-01-19 20:38 ` [PATCH 01/12] perf/core: Add PERF_SAMPLE_WEIGHT_EXT kan.liang
2021-01-26 14:42   ` Peter Zijlstra
2021-01-26 15:33     ` Liang, Kan
2021-01-26 15:55       ` Peter Zijlstra
2021-01-19 20:38 ` [PATCH 02/12] perf/x86/intel: Factor out intel_update_topdown_event() kan.liang
2021-01-19 20:38 ` [PATCH 03/12] perf/x86/intel: Add perf core PMU support for Sapphire Rapids kan.liang
2021-01-26 14:43   ` Peter Zijlstra
2021-01-26 15:34     ` Liang, Kan
2021-01-26 14:44   ` Peter Zijlstra
2021-01-26 15:44     ` Liang, Kan
2021-01-27 19:16       ` Peter Zijlstra
2021-01-26 14:49   ` Peter Zijlstra
2021-01-26 15:37   ` Peter Zijlstra
2021-01-26 16:21     ` Liang, Kan
2021-01-19 20:38 ` [PATCH 04/12] perf/x86/intel: Support CPUID 10.ECX to disable fixed counters kan.liang
2021-01-26 15:44   ` Peter Zijlstra
2021-01-26 15:53   ` Peter Zijlstra [this message]
2021-01-19 20:38 ` [PATCH 05/12] tools headers uapi: Update tools's copy of linux/perf_event.h kan.liang
2021-01-19 20:38 ` [PATCH 06/12] perf tools: Support data block and addr block kan.liang
2021-01-19 20:38 ` [PATCH 07/12] perf c2c: " kan.liang
2021-01-19 20:38 ` [PATCH 08/12] perf tools: Support PERF_SAMPLE_WEIGHT_EXT kan.liang
2021-01-19 20:38 ` [PATCH 09/12] perf report: Support instruction latency kan.liang
2021-01-19 20:38 ` [PATCH 10/12] perf test: Support PERF_SAMPLE_WEIGHT_EXT kan.liang
2021-01-19 20:38 ` [PATCH 11/12] perf stat: Support L2 Topdown events kan.liang
2021-01-19 20:38 ` [PATCH 12/12] perf, tools: Update topdown documentation for Sapphire Rapids kan.liang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YBA662724snCMudn@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=acme@kernel.org \
    --cc=ak@linux.intel.com \
    --cc=eranian@google.com \
    --cc=jolsa@redhat.com \
    --cc=kan.liang@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=namhyung@kernel.org \
    --cc=yao.jin@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox