Messages in this thread Patch in this message | | | Date | Fri, 27 Sep 2013 17:29:08 +0200 | From | Peter Zijlstra <> | Subject | [PATCH] ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED |
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Subject: ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED From: Peter Zijlstra <peterz@infradead.org> Date: Fri Sep 27 17:11:00 CEST 2013
Since we now have two need_resched states; trace the two so we can observe discrepancies.
Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> --- kernel/trace/trace.c | 3 ++- kernel/trace/trace.h | 1 + kernel/trace/trace_output.c | 13 +++++++++++-- 3 files changed, 14 insertions(+), 3 deletions(-)
--- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1509,7 +1509,8 @@ tracing_generic_entry_update(struct trac #endif ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | - (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); + (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | + (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); } EXPORT_SYMBOL_GPL(tracing_generic_entry_update); --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -124,6 +124,7 @@ enum trace_flag_type { TRACE_FLAG_NEED_RESCHED = 0x04, TRACE_FLAG_HARDIRQ = 0x08, TRACE_FLAG_SOFTIRQ = 0x10, + TRACE_FLAG_PREEMPT_RESCHED = 0x20, }; #define TRACE_BUF_SIZE 1024 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -618,8 +618,17 @@ int trace_print_lat_fmt(struct trace_seq (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.'; - need_resched = - (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'; + + if ((entry->flags & TRACE_FLAG_NEED_RESCHED) && + (entry->flags & TRACE_FLAG_PREEMPT_RESCHED)) + need_resched = 'N'; + else if (entry->flags & TRACE_FLAG_NEED_RESCHED) + need_resched = 'n'; + else if (entry->flags & TRACE_FLAG_PREEMPT_RESCHED) + need_resched = 'p'; + else + need_resched = '.'; + hardsoft_irq = (hardirq && softirq) ? 'H' : hardirq ? 'h' :
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