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From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To: srinivas.pandruvada@linux.intel.com, tglx@linutronix.de,
	mingo@redhat.com, peterz@infradead.org, bp@suse.de,
	lenb@kernel.org, rjw@rjwysocki.net, mgorman@techsingularity.net
Cc: x86@kernel.org, linux-pm@vger.kernel.org,
	viresh.kumar@linaro.org, juri.lelli@arm.com,
	linux-kernel@vger.kernel.org
Subject: [RFC/RFT] [PATCH 02/10] cpufreq: intel_pstate: Conditional frequency invariant accounting
Date: Tue, 15 May 2018 21:49:03 -0700	[thread overview]
Message-ID: <20180516044911.28797-3-srinivas.pandruvada@linux.intel.com> (raw)
In-Reply-To: <20180516044911.28797-1-srinivas.pandruvada@linux.intel.com>

intel_pstate has two operating modes: active and passive. In "active"
mode, the in-built scaling governor is used and in "passive" mode,
the driver can be used with any governor like "schedutil". In "active"
mode the utilization values from schedutil is not used and there is
a requirement from high performance computing use cases, not to read
any APERF/MPERF MSRs. In this case no need to use CPU cycles for
frequency invariant accounting by reading APERF/MPERF MSRs.
With this change frequency invariant account is only enabled in
"passive" mode.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
[Note: The tick will be enabled later in the series when hwp dynamic
boost is enabled]

 drivers/cpufreq/intel_pstate.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 17e566af..f686bbe 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2040,6 +2040,8 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver)
 {
 	int ret;
 
+	x86_arch_scale_freq_tick_disable();
+
 	memset(&global, 0, sizeof(global));
 	global.max_perf_pct = 100;
 
@@ -2052,6 +2054,9 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver)
 
 	global.min_perf_pct = min_perf_pct_min();
 
+	if (driver == &intel_cpufreq)
+		x86_arch_scale_freq_tick_enable();
+
 	return 0;
 }
 
-- 
2.9.5

  parent reply	other threads:[~2018-05-16  4:51 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-16  4:49 [RFC/RFT] [PATCH 00/10] Intel_pstate: HWP Dynamic performance boost Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 01/10] x86,sched: Add support for frequency invariance Srinivas Pandruvada
2018-05-16  9:56   ` Peter Zijlstra
2018-05-16  4:49 ` Srinivas Pandruvada [this message]
2018-05-16  7:16   ` [RFC/RFT] [PATCH 02/10] cpufreq: intel_pstate: Conditional frequency invariant accounting Peter Zijlstra
2018-05-16  7:29     ` Peter Zijlstra
2018-05-16  9:07       ` Rafael J. Wysocki
2018-05-16 17:32         ` Srinivas Pandruvada
2018-05-16 15:19   ` Juri Lelli
2018-05-16 15:47     ` Peter Zijlstra
2018-05-16 16:31       ` Juri Lelli
2018-05-17 10:59         ` Juri Lelli
2018-05-17 15:04           ` Juri Lelli
2018-05-17 15:41             ` Srinivas Pandruvada
2018-05-17 16:16               ` Peter Zijlstra
2018-05-17 16:42                 ` Srinivas Pandruvada
2018-05-17 16:56                   ` Rafael J. Wysocki
2018-05-17 18:28                     ` Peter Zijlstra
2018-05-18  7:36                       ` Rafael J. Wysocki
2018-05-18 10:57                       ` Patrick Bellasi
2018-05-18 11:29                         ` Peter Zijlstra
2018-05-18 13:33                           ` Patrick Bellasi
2018-05-30 16:57                             ` Patrick Bellasi
2018-05-18 14:09                           ` Valentin Schneider
2018-05-16 15:58     ` Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 03/10] cpufreq: intel_pstate: Utility functions to boost HWP performance limits Srinivas Pandruvada
2018-05-16  7:22   ` Peter Zijlstra
2018-05-16  9:15     ` Rafael J. Wysocki
2018-05-16 10:43       ` Peter Zijlstra
2018-05-16 15:39         ` Srinivas Pandruvada
2018-05-16 15:41     ` Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 04/10] cpufreq: intel_pstate: Add update_util_hook for HWP Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 05/10] cpufreq: intel_pstate: HWP boost performance on IO Wake Srinivas Pandruvada
2018-05-16  7:37   ` Peter Zijlstra
2018-05-16 17:55     ` Srinivas Pandruvada
2018-05-17  8:19       ` Peter Zijlstra
2018-05-16  9:45   ` Rafael J. Wysocki
2018-05-16 19:28     ` Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 06/10] cpufreq / sched: Add interface to get utilization values Srinivas Pandruvada
2018-05-16  6:40   ` Viresh Kumar
2018-05-16 22:25     ` Srinivas Pandruvada
2018-05-16  8:11   ` Peter Zijlstra
2018-05-16 22:40     ` Srinivas Pandruvada
2018-05-17  7:50       ` Peter Zijlstra
2018-05-16  4:49 ` [RFC/RFT] [PATCH 07/10] cpufreq: intel_pstate: HWP boost performance on busy task migrate Srinivas Pandruvada
2018-05-16  9:49   ` Rafael J. Wysocki
2018-05-16 20:59     ` Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 08/10] cpufreq: intel_pstate: Dyanmically update busy pct Srinivas Pandruvada
2018-05-16  7:43   ` Peter Zijlstra
2018-05-16  7:47   ` Peter Zijlstra
2018-05-16  4:49 ` [RFC/RFT] [PATCH 09/10] cpufreq: intel_pstate: New sysfs entry to control HWP boost Srinivas Pandruvada
2018-05-16  4:49 ` [RFC/RFT] [PATCH 10/10] cpufreq: intel_pstate: enable boost for SKX Srinivas Pandruvada
2018-05-16  7:49   ` Peter Zijlstra
2018-05-16 15:46     ` Srinivas Pandruvada
2018-05-16 15:54       ` Peter Zijlstra
2018-05-17  0:52         ` Srinivas Pandruvada
2018-05-16  6:49 ` [RFC/RFT] [PATCH 00/10] Intel_pstate: HWP Dynamic performance boost Juri Lelli
2018-05-16 15:43   ` Srinivas Pandruvada

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