From mboxrd@z Thu Jan 1 00:00:00 1970 From: Todd E Brandt Subject: Re: [PATCH] PM: trace events for suspend/resume Date: Thu, 22 May 2014 16:50:31 -0700 Message-ID: <20140522235031.GA21923@linux.intel.com> References: <20140519230226.GA14382@linux.intel.com> <2794431.xZpr01emRq@vostro.rjw.lan> <537E7756.1000503@linux.vnet.ibm.com> Reply-To: todd.e.brandt@linux.intel.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga02.intel.com ([134.134.136.20]:32976 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243AbaEVXu2 (ORCPT ); Thu, 22 May 2014 19:50:28 -0400 Content-Disposition: inline In-Reply-To: <537E7756.1000503@linux.vnet.ibm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Srivatsa S. Bhat" Cc: "Rafael J. Wysocki" , Steven Rostedt , linux-pm@vger.kernel.org, rafael.j.wysocki@intel.com On Fri, May 23, 2014 at 03:46:54AM +0530, Srivatsa S. Bhat wrote: > On 05/22/2014 05:31 AM, Rafael J. Wysocki wrote: > > On Monday, May 19, 2014 04:02:26 PM Todd E Brandt wrote: > >> Adds trace events that give finer resolution into suspend/resume. These > >> events are graphed in the timelines generated by the analyze_suspend.py > >> script. They represent large areas of time consumed that are typical in > >> suspend and resume. > >> > >> The event is triggered by calling the function "trace_suspend_resume" > >> with two arguments: a string (the name of the event to be displayed > >> in the timeline), and a boolean (where true is used to denote the start > >> of the timeline event, and false to denote the end). > >> > >> Signed-off-by: Todd Brandt > >> --- > >> drivers/acpi/nvs.c | 6 ++++++ > >> drivers/acpi/osl.c | 3 +++ > >> drivers/base/syscore.c | 5 +++++ > >> include/trace/events/power.h | 19 +++++++++++++++++++ > >> kernel/cpu.c | 9 +++++++++ > >> kernel/power/process.c | 3 +++ > >> kernel/power/suspend.c | 4 ++++ > >> 7 files changed, 49 insertions(+) > >> > >> For more info see: > >> https://01.org/suspendresume/blogs/tebrandt/2014/custom-timeline-event-support-0 > >> > >> I'm also interested to know if any tools depend on the machine_suspend > >> tracepoints, as this patch expands on the same info. I'd be willing to > >> merge the existing machine_suspend calls into this patch and rename > >> everything to suspend_resume provided it doesn't hurt any downstream tools. > >> > >> diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c > >> index de4fe03..b52b686 100644 > >> --- a/drivers/acpi/nvs.c > >> +++ b/drivers/acpi/nvs.c > >> @@ -12,6 +12,7 @@ > >> #include > >> #include > >> #include > >> +#include > >> > >> #include "internal.h" > >> > >> @@ -171,6 +172,7 @@ int suspend_nvs_save(void) > >> { > >> struct nvs_page *entry; > >> > >> + trace_suspend_resume("save_nvs_memory", true); > >> printk(KERN_INFO "PM: Saving platform NVS memory\n"); > >> > >> list_for_each_entry(entry, &nvs_list, node) > >> @@ -185,11 +187,13 @@ int suspend_nvs_save(void) > >> } > >> if (!entry->kaddr) { > >> suspend_nvs_free(); > >> + trace_suspend_resume("save_nvs_memory", false); > >> return -ENOMEM; > >> } > >> memcpy(entry->data, entry->kaddr, entry->size); > >> } > >> > >> + trace_suspend_resume("save_nvs_memory", false); > >> return 0; > >> } > >> > >> @@ -203,10 +207,12 @@ void suspend_nvs_restore(void) > >> { > >> struct nvs_page *entry; > >> > >> + trace_suspend_resume("restore_nvs_memory", true); > >> printk(KERN_INFO "PM: Restoring platform NVS memory\n"); > >> > >> list_for_each_entry(entry, &nvs_list, node) > >> if (entry->data) > >> memcpy(entry->kaddr, entry->data, entry->size); > >> + trace_suspend_resume("restore_nvs_memory", false); > >> } > >> #endif > >> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c > >> index 6776c59..b65a77a 100644 > >> --- a/drivers/acpi/osl.c > >> +++ b/drivers/acpi/osl.c > >> @@ -44,6 +44,7 @@ > >> #include > >> #include > >> #include > >> +#include > >> > >> #include > >> #include > >> @@ -835,7 +836,9 @@ acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler) > >> > >> void acpi_os_sleep(u64 ms) > >> { > >> + trace_suspend_resume("acpi_os_sleep", true); > >> msleep(ms); > >> + trace_suspend_resume("acpi_os_sleep", false); > >> } > > > > This function doesn't have anything to do with system suspend/resume. > > It is for waiting. :-) > > > > The rest of the patch looks OK to me. > > > > Steven, what about the tracing angle? > > > > Hi Todd, > > This might be a silly question, but the suspend_enter() function invokes > ftrace_stop() before suspending the machine, and restarts ftrace after > resume. And your patch seems to instrument code further down (deeper) > in the suspend/resume path (such as disable_nonboot_cpus() for example). > Doesn't the ftrace stop/start pose any problem for this patch? I put a patch in the kernel a few months back that allowed ftrace to function all the way through to disable/enable_nonboot_cpus. So the actual trace code includes everything up to the actual CPU suspend/resume. And also (as Steven mentioned), the tracepoint activity isn't controlled via ftrace_start/ftrace_stop, those are for tracer based logging. > > Regards, > Srivatsa S. Bhat > > > >> > >> void acpi_os_stall(u32 us) > >> diff --git a/drivers/base/syscore.c b/drivers/base/syscore.c > >> index e8d11b6..c2fd5d4 100644 > >> --- a/drivers/base/syscore.c > >> +++ b/drivers/base/syscore.c > >> @@ -10,6 +10,7 @@ > >> #include > >> #include > >> #include > >> +#include > >> > >> static LIST_HEAD(syscore_ops_list); > >> static DEFINE_MUTEX(syscore_ops_lock); > >> @@ -49,6 +50,7 @@ int syscore_suspend(void) > >> struct syscore_ops *ops; > >> int ret = 0; > >> > >> + trace_suspend_resume("syscore_suspend", true); > >> pr_debug("Checking wakeup interrupts\n"); > >> > >> /* Return error code if there are any wakeup interrupts pending. */ > >> @@ -70,6 +72,7 @@ int syscore_suspend(void) > >> "Interrupts enabled after %pF\n", ops->suspend); > >> } > >> > >> + trace_suspend_resume("syscore_suspend", false); > >> return 0; > >> > >> err_out: > >> @@ -92,6 +95,7 @@ void syscore_resume(void) > >> { > >> struct syscore_ops *ops; > >> > >> + trace_suspend_resume("syscore_resume", true); > >> WARN_ONCE(!irqs_disabled(), > >> "Interrupts enabled before system core resume.\n"); > >> > >> @@ -103,6 +107,7 @@ void syscore_resume(void) > >> WARN_ONCE(!irqs_disabled(), > >> "Interrupts enabled after %pF\n", ops->resume); > >> } > >> + trace_suspend_resume("syscore_resume", false); > >> } > >> EXPORT_SYMBOL_GPL(syscore_resume); > >> #endif /* CONFIG_PM_SLEEP */ > >> diff --git a/include/trace/events/power.h b/include/trace/events/power.h > >> index 9a7e08d..1d9fd76 100644 > >> --- a/include/trace/events/power.h > >> +++ b/include/trace/events/power.h > >> @@ -151,6 +151,25 @@ TRACE_EVENT(device_pm_report_time, > >> __entry->ops_time, __entry->error) > >> ); > >> > >> +TRACE_EVENT(suspend_resume, > >> + > >> + TP_PROTO(char *action, bool start), > >> + > >> + TP_ARGS(action, start), > >> + > >> + TP_STRUCT__entry( > >> + __string(action, action) > >> + __field(bool, start) > >> + ), > >> + > >> + TP_fast_assign( > >> + __assign_str(action, action); > >> + __entry->start = start; > >> + ), > >> + > >> + TP_printk("%s %s", __get_str(action), (__entry->start)?"begin":"end") > >> +); > >> + > >> DECLARE_EVENT_CLASS(wakeup_source, > >> > >> TP_PROTO(const char *name, unsigned int state), > >> diff --git a/kernel/cpu.c b/kernel/cpu.c > >> index a9e710e..7aa30ec 100644 > >> --- a/kernel/cpu.c > >> +++ b/kernel/cpu.c > >> @@ -20,6 +20,7 @@ > >> #include > >> #include > >> #include > >> +#include > >> > >> #include "smpboot.h" > >> > >> @@ -509,6 +510,7 @@ static cpumask_var_t frozen_cpus; > >> int disable_nonboot_cpus(void) > >> { > >> int cpu, first_cpu, error = 0; > >> + char buf[12]; > >> > >> cpu_maps_update_begin(); > >> first_cpu = cpumask_first(cpu_online_mask); > >> @@ -522,7 +524,10 @@ int disable_nonboot_cpus(void) > >> for_each_online_cpu(cpu) { > >> if (cpu == first_cpu) > >> continue; > >> + sprintf(buf, "CPU%u_OFF", cpu); > >> + trace_suspend_resume(buf, true); > >> error = _cpu_down(cpu, 1); > >> + trace_suspend_resume(buf, false); > >> if (!error) > >> cpumask_set_cpu(cpu, frozen_cpus); > >> else { > >> @@ -554,6 +559,7 @@ void __weak arch_enable_nonboot_cpus_end(void) > >> void __ref enable_nonboot_cpus(void) > >> { > >> int cpu, error; > >> + char buf[10]; > >> > >> /* Allow everyone to use the CPU hotplug again */ > >> cpu_maps_update_begin(); > >> @@ -566,7 +572,10 @@ void __ref enable_nonboot_cpus(void) > >> arch_enable_nonboot_cpus_begin(); > >> > >> for_each_cpu(cpu, frozen_cpus) { > >> + sprintf(buf, "CPU%u_ON", cpu); > >> + trace_suspend_resume(buf, true); > >> error = _cpu_up(cpu, 1); > >> + trace_suspend_resume(buf, false); > >> if (!error) { > >> printk(KERN_INFO "CPU%d is up\n", cpu); > >> continue; > >> diff --git a/kernel/power/process.c b/kernel/power/process.c > >> index 06ec886..4aec2d9 100644 > >> --- a/kernel/power/process.c > >> +++ b/kernel/power/process.c > >> @@ -17,6 +17,7 @@ > >> #include > >> #include > >> #include > >> +#include > >> > >> /* > >> * Timeout for stopping processes > >> @@ -175,6 +176,7 @@ void thaw_processes(void) > >> struct task_struct *g, *p; > >> struct task_struct *curr = current; > >> > >> + trace_suspend_resume("thaw_processes", true); > >> if (pm_freezing) > >> atomic_dec(&system_freezing_cnt); > >> pm_freezing = false; > >> @@ -201,6 +203,7 @@ void thaw_processes(void) > >> > >> schedule(); > >> printk("done.\n"); > >> + trace_suspend_resume("thaw_processes", false); > >> } > >> > >> void thaw_kernel_threads(void) > >> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c > >> index 8233cd4..c7e3e9f 100644 > >> --- a/kernel/power/suspend.c > >> +++ b/kernel/power/suspend.c > >> @@ -147,7 +147,9 @@ static int suspend_prepare(suspend_state_t state) > >> if (error) > >> goto Finish; > >> > >> + trace_suspend_resume("freeze_processes", true); > >> error = suspend_freeze_processes(); > >> + trace_suspend_resume("freeze_processes", false); > >> if (!error) > >> return 0; > >> > >> @@ -337,9 +339,11 @@ static int enter_state(suspend_state_t state) > >> if (state == PM_SUSPEND_FREEZE) > >> freeze_begin(); > >> > >> + trace_suspend_resume("sync_filesystems", true); > >> printk(KERN_INFO "PM: Syncing filesystems ... "); > >> sys_sync(); > >> printk("done.\n"); > >> + trace_suspend_resume("sync_filesystems", false); > >> > >> pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); > >> error = suspend_prepare(state); > >