aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/cpu/cpufreq
diff options
context:
space:
mode:
authorArjan van de Ven <arjan@infradead.org>2008-11-23 16:49:58 -0800
committerIngo Molnar <mingo@elte.hu>2008-11-26 08:29:32 +0100
commitf3f47a6768a29448866da4422b6f6bee485c947f (patch)
treeba4bf1b79cbd13412871eec50250294d7140fd09 /arch/x86/kernel/cpu/cpufreq
parent509dceef6470442d8c7b8a43ec34125205840b3c (diff)
tracing: add "power-tracer": C/P state tracer to help power optimization
Impact: new "power-tracer" ftrace plugin This patch adds a C/P-state ftrace plugin that will generate detailed statistics about the C/P-states that are being used, so that we can look at detailed decisions that the C/P-state code is making, rather than the too high level "average" that we have today. An example way of using this is: mount -t debugfs none /sys/kernel/debug echo cstate > /sys/kernel/debug/tracing/current_tracer echo 1 > /sys/kernel/debug/tracing/tracing_enabled sleep 1 echo 0 > /sys/kernel/debug/tracing/tracing_enabled cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/cpufreq')
-rw-r--r--arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 8e48c5d4467..88ea02dcb62 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -33,6 +33,7 @@
#include <linux/cpufreq.h>
#include <linux/compiler.h>
#include <linux/dmi.h>
+#include <linux/ftrace.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
@@ -391,6 +392,7 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
unsigned int next_perf_state = 0; /* Index into perf table */
unsigned int i;
int result = 0;
+ struct power_trace it;
dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
@@ -427,6 +429,8 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
}
}
+ trace_power_mark(&it, POWER_PSTATE, next_perf_state);
+
switch (data->cpu_feature) {
case SYSTEM_INTEL_MSR_CAPABLE:
cmd.type = SYSTEM_INTEL_MSR_CAPABLE;