Commit e5137b50 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED

Since the introduction of PREEMPT_NEED_RESCHED in:

  f27dde8d

 ("sched: Add NEED_RESCHED to the preempt_count")

we need to be able to look at both TIF_NEED_RESCHED and
PREEMPT_NEED_RESCHED to understand the full preemption behaviour.

Add it to the trace output.
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 7053ea1a
......@@ -655,7 +655,11 @@ explains which is which.
read the irq flags variable, an 'X' will always
be printed here.
need-resched: 'N' task need_resched is set, '.' otherwise.
need-resched:
'N' both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED is set,
'n' only TIF_NEED_RESCHED is set,
'p' only PREEMPT_NEED_RESCHED is set,
'.' otherwise.
hardirq/softirq:
'H' - hard irq occurred inside a softirq.
......
......@@ -1509,7 +1509,8 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
#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);
......
......@@ -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
......
......@@ -618,8 +618,23 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
'.';
need_resched =
(entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
TRACE_FLAG_PREEMPT_RESCHED)) {
case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
need_resched = 'N';
break;
case TRACE_FLAG_NEED_RESCHED:
need_resched = 'n';
break;
case TRACE_FLAG_PREEMPT_RESCHED:
need_resched = 'p';
break;
default:
need_resched = '.';
break;
}
hardsoft_irq =
(hardirq && softirq) ? 'H' :
hardirq ? 'h' :
......
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