Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757805Ab0FIN5i (ORCPT ); Wed, 9 Jun 2010 09:57:38 -0400 Received: from mailout2.zih.tu-dresden.de ([141.30.67.73]:36488 "EHLO mailout2.zih.tu-dresden.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752589Ab0FIN5g convert rfc822-to-8bit (ORCPT ); Wed, 9 Jun 2010 09:57:36 -0400 Subject: [PATCH] power_end event (Resend) From: Robert =?ISO-8859-1?Q?Sch=F6ne?= To: Ingo Molnar , Peter Zijlstra , Arjan van de Ven , Thomas Gleixner Cc: linux-kernel Content-Type: text/plain; charset="UTF-8" Date: Wed, 09 Jun 2010 15:57:27 +0200 Message-ID: <1276091847.1763.18.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 8BIT X-TUD-Virus-Scanned: mailout2.zih.tu-dresden.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3420 Lines: 98 Original Mail was sent at 2010/05/14 10:38:43 CEST Hi, I reported the power_end tracing problem earlier this year (http://lkml.org/lkml/2010/2/24/79) and sent a patch which worked for my system. However this patch would have not worked on other systems (as for example Arjans). It would had lead to a double posting of these events. However. Here's a diff that should fix the problem on the correct spot. The reason that it worked for Arjan and not for me is that his system uses drivers/acpi/processor_idle.c when idling, mine uses the cpu_idle thread from arch/x86/kernel/process_64.c. A comparable idle thread also exists for 32 bit x86, so I added it in process_32.c too. However, is there any standard about where to report the start and end events? Currently it's the idle routine, which creates the power_start event, the routine which calls the idle_routine on the other hand creates the power_end event. For these patches, I'm not sure whether the power_end event should even be reported. On kernels, which use the repnop loop when idling, there won't be a switch to another c-state and therefore no power_start event, the power_end event could belong to. Would that be a problem? If it would, the only way to fix this would be to move the power_end events into the idle routines, since cpu_idle is dumb and does not know whats behind pm_idle. Robert PS: I hand over the smp_processor_id() to power_end since i hope that the changed interface defined in http://lkml.org/lkml/2010/4/27/271 will be part of the standard tree one day. As long as this new interface is not included in the standard tree, this patch won't make no harm. When it will be included, this code does not have to be touched anymore. Signed-off-by: Robert Schöne arch/x86/kernel/process_32.c | 4 ++++ arch/x86/kernel/process_64.c | 5 +++++ 2 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index f6c6266..134f5f9 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -58,6 +58,8 @@ #include #include +#include + asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); /* @@ -112,6 +114,8 @@ void cpu_idle(void) stop_critical_timings(); pm_idle(); start_critical_timings(); + + trace_power_end(smp_processor_id()); } tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 17cb329..01c55ed 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -52,6 +52,8 @@ #include #include +#include + asmlinkage extern void ret_from_fork(void); DEFINE_PER_CPU(unsigned long, old_rsp); @@ -139,6 +141,9 @@ void cpu_idle(void) stop_critical_timings(); pm_idle(); start_critical_timings(); + + trace_power_end(smp_processor_id()); + /* In many cases the interrupt that ended idle has already called exit_idle. But some idle loops can be woken up without interrupt. */ -- 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/