Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758919Ab1FAMgI (ORCPT ); Wed, 1 Jun 2011 08:36:08 -0400 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:40681 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758897Ab1FAMgF (ORCPT ); Wed, 1 Jun 2011 08:36:05 -0400 Date: Wed, 1 Jun 2011 18:05:54 +0530 From: Deepthi Dharwar To: linuxppc-dev@ozlabs.org, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH] perf_events: Enable idle state tracing for pseries (ppc64) Message-ID: <20110601123554.GA12492@deepthi.in.ibm.com> Reply-To: deepthi@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4397 Lines: 129 Hi, Please find below a patch, which has perf_events added for pseries (ppc64) platform in order to emit the trace required for perf timechart. It essentially enables perf timechart for pseries platfrom to analyse power savings events like cpuidle states. Steps to enable and disable the trace; 1) Mount debugfs; mount -t debugfs none /sys/kernel/debug 2) Then, enable the event using; echo 1 > /sys/kernel/debug/tracing/events/power/cpu_idle/enable 3) The output of the trace can be seen in /sys/kernel/debug/tracing/trace 4) To disable the trace use; echo 0 > sys/kernel/debug/tracing/events/power/cpu_idle/enable Trace .svg o/p can be viewed for pseries (ppc64) systems showing various cpu-idle states as a part of perf timechart tool. References: http://blog.fenrus.org/?p=5 Issue command 'perf timechart record' to enable tracing. This generates the trace and records in perf.data file by default. One can generate output.svg file by issuing 'perf timechart'. Sample o/p from the trace file: =============================== State 1 -> Snooze State 2 -> Cede # tracer: nop # TASK-PID CPU# TIMESTAMP FUNCTION | | | | | -0 [000] 292.482314: cpu_idle: state=1 cpu_id=0 ^^ Enter Snooze -0 [001] 292.482363: cpu_idle: state=1 cpu_id=1 -0 [000] 292.492315: cpu_idle: state=4294967295 cpu_id=0 ^^ Exit Snooze -0 [000] 292.492316: cpu_idle: state=2 cpu_id=0 ^^ Enter Cede -0 [001] 292.492364: cpu_idle: state=4294967295 cpu_id=1 -0 [001] 292.492364: cpu_idle: state=2 cpu_id=1 -0 [000] 292.504198: cpu_idle: state=4294967295 cpu_id=0 ^^Exit Cede -0 [000] 292.504204: cpu_idle: state=1 cpu_id=0 -0 [001] 292.504921: cpu_idle: state=4294967295 cpu_id=1 -0 [001] 292.504936: cpu_idle: state=1 cpu_id=1 -0 [000] 292.514205: cpu_idle: state=4294967295 cpu_id=0 This patch applies on 2.6.39 and tested on a IBM POWER7 machine. -Deepthi Adding perf events to trace various cpu idle states on ppc64 (pseries) platform. Signed-off-by: Deepthi Dharwar pseries.h | 4 ++++ setup.c | 14 ++++++++++++++ 2 files changed, 18 insertions(+) Index: linux-2.6.39/arch/powerpc/platforms/pseries/setup.c =================================================================== --- linux-2.6.39.orig/arch/powerpc/platforms/pseries/setup.c 2011-05-19 00:06:34.000000000 -0400 +++ linux-2.6.39/arch/powerpc/platforms/pseries/setup.c 2011-06-01 07:46:00.000000000 -0400 @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -582,6 +583,10 @@ * while, do so. */ if (snooze) { + + trace_power_start(POWER_CSTATE, CPU_IDLE_SNOOZE, cpu); + trace_cpu_idle(CPU_IDLE_SNOOZE, cpu); + start_snooze = get_tb() + snooze * tb_ticks_per_usec; local_irq_enable(); set_thread_flag(TIF_POLLING_NRFLAG); @@ -602,9 +607,19 @@ goto out; } + trace_power_end(cpu); + trace_cpu_idle(PWR_EVENT_EXIT, cpu); + + trace_power_start(POWER_CSTATE, CPU_IDLE_CEDE, cpu); + trace_cpu_idle(CPU_IDLE_CEDE, cpu); + cede_processor(); out: + + trace_power_end(cpu); + trace_cpu_idle(PWR_EVENT_EXIT, cpu); + HMT_medium(); out_purr = mfspr(SPRN_PURR); get_lppaca()->wait_state_cycles += out_purr - in_purr; Index: linux-2.6.39/arch/powerpc/platforms/pseries/pseries.h =================================================================== --- linux-2.6.39.orig/arch/powerpc/platforms/pseries/pseries.h 2011-05-19 00:06:34.000000000 -0400 +++ linux-2.6.39/arch/powerpc/platforms/pseries/pseries.h 2011-06-01 07:53:24.000000000 -0400 @@ -12,6 +12,9 @@ #include +#define CPU_IDLE_SNOOZE 1 +#define CPU_IDLE_CEDE 2 + struct device_node; extern void request_event_sources_irqs(struct device_node *np, @@ -56,4 +59,5 @@ extern int dlpar_attach_node(struct device_node *); extern int dlpar_detach_node(struct device_node *); + #endif /* _PSERIES_PSERIES_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/