linux-kernel - [PATCH] cpuidle: Add an addtional trace for demoted c-states

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1319197567-8573-1-git-send-email-john.mathew@intel.com>
Date:	Fri, 21 Oct 2011 14:46:07 +0300
From:	John Mathew <john.mathew@...el.com>
To:	linux-kernel@...r.kernel.org
Cc:	len.brown@...el.com, pierre.tardy@...el.com, trenn@...e.de,
	rostedt@...dmis.org, fweisbec@...il.com, mingo@...hat.com,
	John Mathew <john.mathew@...el.com>
Subject: [PATCH] cpuidle: Add an addtional trace for demoted c-states

This patch enables tracing of c-states that the device
eventually goes in to, which might be different from what
the governor had retuned. This scenario occurs in platforms
like Intel Medfield. Power tools like pytimechart will be
able to display accurate c-state transitions with the help of
this trace.

Signed-off-by: John Mathew <john.mathew@...el.com>
---
 drivers/cpuidle/cpuidle.c    |    3 +++
 include/trace/events/power.h |   23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index d4c5423..3d787ef 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -110,6 +110,9 @@ int cpuidle_idle_call(void)
 
 	dev->last_residency = target_state->enter(dev, target_state);
 
+	if (dev->last_state != target_state)
+		trace_power_demoted(POWER_CSTATE, dev->last_state->name, dev->cpu);
+
 	trace_power_end(dev->cpu);
 	trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
 
diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index 1bcc2a8..941dc1a 100644
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -101,6 +101,29 @@ DEFINE_EVENT(power, power_start,
 	TP_ARGS(type, state, cpu_id)
 );
 
+TRACE_EVENT(power_demoted,
+
+	TP_PROTO(unsigned int type, char *state, unsigned int cpu_id),
+
+	TP_ARGS(type, state, cpu_id),
+
+	TP_STRUCT__entry(
+		__field(	u64,		type		)
+		__string(	state,		state		)
+		__field(	u64,		cpu_id		)
+	),
+
+	TP_fast_assign(
+		__entry->type = type;
+		__assign_str(state, state);
+		__entry->cpu_id = cpu_id;
+	),
+
+	TP_printk("type=%lu state=%s cpu_id=%lu", (unsigned long)__entry->type,
+		 __get_str(state), (unsigned long)__entry->cpu_id)
+
+);
+
 DEFINE_EVENT(power, power_frequency,
 
 	TP_PROTO(unsigned int type, unsigned int state, unsigned int cpu_id),
-- 
1.7.4.1

---------------------------------------------------------------------
Intel Finland Oy
Registered Address: PL 281, 00181 Helsinki 
Business Identity Code: 0357606 - 4 
Domiciled in Helsinki 

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/