From 8a58a34ba479d42b3ef28f8ffd9e245a81a7786f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 10 Feb 2017 16:41:15 +0100 Subject: [PATCH] timers: Make flags output in the timer_start tracepoint useful The timer flags in the timer_start trace event contain lots of useful information, but the meaning is not clear in the trace output. Making tools rely on the bit positions is bad as they might change over time. Decode the flags in the print out. Tools can retrieve the bits and their meaning from the trace format file. Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1702101639290.4036@nanos Requested-by: Arjan van de Ven Signed-off-by: Thomas Gleixner Signed-off-by: Steven Rostedt (VMware) --- include/linux/timer.h | 2 ++ include/trace/events/timer.h | 14 ++++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/include/linux/timer.h b/include/linux/timer.h index 51d601f192d4..a17f915f9456 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -66,6 +66,8 @@ struct timer_list { #define TIMER_ARRAYSHIFT 22 #define TIMER_ARRAYMASK 0xFFC00000 +#define TIMER_TRACE_FLAGMASK (TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE) + #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \ .entry = { .next = TIMER_ENTRY_STATIC }, \ .function = (_function), \ diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index 1448637616d6..f6d8fea6df77 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -36,6 +36,13 @@ DEFINE_EVENT(timer_class, timer_init, TP_ARGS(timer) ); +#define decode_timer_flags(flags) \ + __print_flags(flags, "|", \ + { TIMER_MIGRATING, "M" }, \ + { TIMER_DEFERRABLE, "D" }, \ + { TIMER_PINNED, "P" }, \ + { TIMER_IRQSAFE, "I" }) + /** * timer_start - called when the timer is started * @timer: pointer to struct timer_list @@ -65,9 +72,12 @@ TRACE_EVENT(timer_start, __entry->flags = flags; ), - TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] flags=0x%08x", + TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] cpu=%u idx=%u flags=%s", __entry->timer, __entry->function, __entry->expires, - (long)__entry->expires - __entry->now, __entry->flags) + (long)__entry->expires - __entry->now, + __entry->flags & TIMER_CPUMASK, + __entry->flags >> TIMER_ARRAYSHIFT, + decode_timer_flags(__entry->flags & TIMER_TRACE_FLAGMASK)) ); /**