Messages in this thread Patch in this message | | | From | Alex Neronskiy <> | Subject | [PATCH/RFC v9 2/2] Use trace events to report stalls | Date | Wed, 17 Aug 2011 13:36:09 -0700 |
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Signed-off-by: Alex Neronskiy <zakmagnus@chromium.org> --- This outputs both the numerical representation of the stall as well as a stack trace. The trace, unlike the number, is always output, regardless of what debug/tracing/events/watchdog/enable says. I don't know how to hook into that.
kernel/trace_watchdog.h | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/watchdog.c | 23 +++++++++++------------ 2 files changed, 54 insertions(+), 12 deletions(-) create mode 100644 kernel/trace_watchdog.h
diff --git a/kernel/trace_watchdog.h b/kernel/trace_watchdog.h new file mode 100644 index 0000000..1401d27f --- /dev/null +++ b/kernel/trace_watchdog.h @@ -0,0 +1,43 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM watchdog + +#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_WATCHDOG_H + +#include <linux/tracepoint.h> +#include <linux/stacktrace.h> + +TRACE_EVENT(soft_stall, + TP_PROTO(unsigned long stall), + TP_ARGS(stall), + TP_STRUCT__entry( + __field(unsigned long, stall) + ), + TP_fast_assign( + __entry->stall = stall; + ), + TP_printk("Soft stall: %lums", __entry->stall) +); + +#ifdef CONFIG_HARDLOCKUP_DETECTOR +TRACE_EVENT(hard_stall, + TP_PROTO(unsigned long stall), + TP_ARGS(stall), + TP_STRUCT__entry( + __field(unsigned long, stall) + ), + TP_fast_assign( + __entry->stall = stall; + ), + TP_printk("Hard stall: %lu", __entry->stall) +); +#endif /* CONFIG_HARDLOCKUP_DETECTOR */ + +#endif /* _TRACE_WATCHDOG_H */ + +#undef TRACE_INCLUDE_PATH +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_PATH . + +#define TRACE_INCLUDE_FILE trace_watchdog +#include <trace/define_trace.h> diff --git a/kernel/watchdog.c b/kernel/watchdog.c index d4c51cc..18385ed 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -27,6 +27,9 @@ #include <asm/irq_regs.h> #include <linux/perf_event.h> +#define CREATE_TRACE_POINTS +#include "trace_watchdog.h" + int watchdog_enabled = 1; int __read_mostly watchdog_thresh = 10; static unsigned long worst_softstall; @@ -208,7 +211,7 @@ void touch_softlockup_watchdog_sync(void) #ifdef CONFIG_HARDLOCKUP_DETECTOR /* watchdog detector functions */ -static void update_hardstall(unsigned long stall, int this_cpu) +static void update_hardstall(unsigned long stall) { int update_stall = 0; @@ -222,10 +225,8 @@ static void update_hardstall(unsigned long stall, int this_cpu) } if (update_stall) { - printk(KERN_WARNING "LOCKUP may be in progress!" - "Worst hard stall seen on CPU#%d: %lu interrupts missed\n", - this_cpu, stall); - dump_stack(); + trace_hard_stall(stall); + trace_dump_stack(); } } @@ -245,12 +246,12 @@ static int is_hardlockup(int this_cpu) if (ints_missed >= hardlockup_thresh) return 1; - update_hardstall(ints_missed, this_cpu); + update_hardstall(ints_missed); return 0; } #endif -static void update_softstall(unsigned long stall, int this_cpu) +static void update_softstall(unsigned long stall) { int update_stall = 0; if (stall > get_softstall_thresh() && @@ -264,10 +265,8 @@ static void update_softstall(unsigned long stall, int this_cpu) } if (update_stall) { - printk(KERN_WARNING "LOCKUP may be in progress!" - "Worst soft stall seen on CPU#%d: %lums\n", - this_cpu, stall); - dump_stack(); + trace_soft_stall(stall); + trace_dump_stack(); } } @@ -280,7 +279,7 @@ static int is_softlockup(unsigned long touch_ts, int this_cpu) if (time_after(now, touch_ts + 1000 * get_softlockup_thresh())) return stall; - update_softstall(stall, this_cpu); + update_softstall(stall); return 0; } -- 1.7.3.1
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