From: Harry Pan <harry.pan@intel.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: gs0622@gmail.com, Harry Pan <harry.pan@intel.com>,
Vishwanath Somayaji <vishwanath.somayaji@intel.com>,
Andy Shevchenko <andy@infradead.org>,
platform-driver-x86@vger.kernel.org,
Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>,
Darren Hart <dvhart@infradead.org>
Subject: [PATCH v2] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds
Date: Tue, 28 May 2019 10:57:27 +0800 [thread overview]
Message-ID: <20190528025727.6014-1-harry.pan@intel.com> (raw)
In-Reply-To: <20190527130811.450-1-harry.pan@intel.com>
Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000
This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.
v2: restore the accidentally deleted newline, no function change.
Signed-off-by: Harry Pan <harry.pan@intel.com>
---
drivers/platform/x86/intel_pmc_core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index f2c621b55f49..c78918a7e731 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -24,6 +24,7 @@
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/msr.h>
+#include <asm/tsc.h>
#include "intel_pmc_core.h"
@@ -738,8 +739,8 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
continue;
- seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
- pcstate_count);
+ seq_printf(s, "%-8s : %llu\n", map[index].name,
+ pcstate_count * 1000 / tsc_khz);
}
return 0;
--
2.20.1
next prev parent reply other threads:[~2019-05-28 2:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-27 13:08 [PATCH] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds Harry Pan
2019-05-28 2:53 ` Harry Pan
2019-05-28 2:57 ` Harry Pan [this message]
2019-06-19 8:28 ` [PATCH v3] " Harry Pan
2019-06-29 13:24 ` Andy Shevchenko
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