On Thu, Jan 27, 2011 at 11:04:09AM +0100, Vincent Guittot wrote: > On 26 January 2011 18:32, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote: > > On Tue, Jan 25, 2011 at 09:54:59AM +0100, Vincent Guittot wrote: > >> Please find below a new proposal for adding trace events for cpu hotplug. > >> The goal is to measure the latency of each part (kernel, architecture) > >> and also to trace the cpu hotplug activity with other power events. I > >> have tested these traces events on an arm platform. > >> > >> Subject: [PATCH 1/2] add cpu hotplug tracepoints > >> > >> this patch adds new events for cpu hotplug tracing > >> * plug/unplug sequence > >> * core and architecture latency measurements > >> > >> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx> > >> --- > >> kernel/cpu.c | 17 +++++++++++++++++ > >> 1 files changed, 17 insertions(+), 0 deletions(-) > >> > >> diff --git a/kernel/cpu.c b/kernel/cpu.c > >> index 156cc55..f04e9cf 100644 > >> --- a/kernel/cpu.c > >> +++ b/kernel/cpu.c > >> @@ -16,6 +16,9 @@ > >> #include <linux/mutex.h> > >> #include <linux/gfp.h> > >> > >> +#define CREATE_TRACE_POINTS > >> +#include <trace/events/cpu_hotplug.h> > >> + > >> #ifdef CONFIG_SMP > >> /* Serializes the updates to cpu_online_mask, cpu_present_mask */ > >> static DEFINE_MUTEX(cpu_add_remove_lock); > >> @@ -200,7 +203,9 @@ static int __ref take_cpu_down(void *_param) > >> int err; > >> > >> /* Ensure this CPU doesn't handle any more interrupts. */ > >> + trace_cpu_hotplug_arch_disable_start((unsigned int)(param->hcpu)); > >> err = __cpu_disable(); > >> + trace_cpu_hotplug_arch_disable_end((unsigned int)(param->hcpu)); > > > > You should create a cpu var instead of doing that not very beautiful cast > > twice. > > > > OK > > > Probably we should eventually rename arch_disable into just disable. > > > > And same for die, because otherwise the name is quite long. > > > > If we remove the arch extension of these names, we will have > trace_cpu_hotplug_arch_up for __cpu_up (trace_cpu_hotplug_up is > already used) and trace_cpu_hotplug_disable for __cpu_disable. would > that be acceptable ? You're right. Well, we could rename cpu_hotplug_arch_up into cpu_hotplug_enable, but the overall result makes it confusing. Let's keep it that way. -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
