Messages in this thread Patch in this message | | | Date | Tue, 30 Apr 2013 13:27:20 -0400 | From | "Frank Ch. Eigler" <> | Subject | Re: systemtap broken by removal of register_timer_hook |
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Hi -
> [...] How about creating trace_tick() in > include/trace/events/timer.h and call it from tick_periodic() and > tick_sched_handle(). [...]
Like this?
From facee64445c0dcc717e99c474c5c7dcdd31b9a74 Mon Sep 17 00:00:00 2001 From: "Frank Ch. Eigler" <fche@redhat.com> Date: Wed, 3 Apr 2013 10:35:21 -0400 Subject: [PATCH] profiling: add tick tracepoint
Commit ba6fdda4 removed the timer_hook mechanism for modules to listen to profiling timer ticks (without having to set up more complicated perf mechanisms). To reduce the impact on out-of-tree users such as systemtap, a TRACE_EVENT-flavoured tracepoint is added in its place, invoked right beside profile_tick() in kernel/time/tick-*.c. Tested with perf and systemtap.
Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Frank Ch. Eigler <fche@redhat.com> --- include/trace/events/timer.h | 20 ++++++++++++++++++++ kernel/time/tick-common.c | 2 ++ kernel/time/tick-sched.c | 2 ++ 3 files changed, 24 insertions(+)
diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index 425bcfe..ec4c2d0 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -323,6 +323,26 @@ TRACE_EVENT(itimer_expire, (int) __entry->pid, (unsigned long long)__entry->now) ); + +struct pt_regs; + +/** + * tick - called when the profiling timer ticks + * @regs: pointer to struct pt_regs* + */ +TRACE_EVENT(tick, + TP_PROTO(struct pt_regs *regs), + TP_ARGS(regs), + TP_STRUCT__entry( + __field( struct pt_regs*, regs ) + ), + TP_fast_assign( + __entry->regs = regs; + ), + TP_printk("ip=%p", (void *) instruction_pointer(__entry->regs)) +); + + #endif /* _TRACE_TIMER_H */ /* This part must be outside protection */ diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index b1600a6..5f4227f 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -18,6 +18,7 @@ #include <linux/percpu.h> #include <linux/profile.h> #include <linux/sched.h> +#include <trace/events/timer.h> #include <asm/irq_regs.h> @@ -74,6 +75,7 @@ static void tick_periodic(int cpu) update_process_times(user_mode(get_irq_regs())); profile_tick(CPU_PROFILING); + trace_tick(get_irq_regs()); } /* diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index a19a399..447be56 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -21,6 +21,7 @@ #include <linux/sched.h> #include <linux/module.h> #include <linux/irq_work.h> +#include <trace/events/timer.h> #include <asm/irq_regs.h> @@ -140,6 +141,7 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) #endif update_process_times(user_mode(regs)); profile_tick(CPU_PROFILING); + trace_tick(get_irq_regs()); } /* -- 1.8.2
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