diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2013-10-04 17:28:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-11-11 12:43:39 +0100 |
| commit | e5137b50a0640009fd63a3e65c14bc6e1be8796a (patch) | |
| tree | ef8475a7281a78d7ad7bd6694b44c8a32c12f970 | |
| parent | stop_machine: Fix race between stop_two_cpus() and stop_cpus() (diff) | |
| download | linux-e5137b50a0640009fd63a3e65c14bc6e1be8796a.tar.xz linux-e5137b50a0640009fd63a3e65c14bc6e1be8796a.zip | |
ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
Since the introduction of PREEMPT_NEED_RESCHED in:
f27dde8deef3 ("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: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven 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: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | Documentation/trace/ftrace.txt | 6 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 3 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_output.c | 19 |
4 files changed, 25 insertions, 4 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index ea2d35d64d26..bd365988e8d8 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -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. diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7974ba20557d..d9fea7dfd5d3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -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); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 10c86fb7a2b4..73d08aa25b55 100644 --- 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 diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 34e7cbac0c9c..ed32284fbe32 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -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' : |