diff options
| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2018-01-16 05:51:39 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-03-11 00:05:50 +0300 |
| commit | 00b4145298aeb05a2d110117ed18148cb21ebd14 (patch) | |
| tree | 610810c0d71a584fe63b555d07dafba619ab8054 /kernel | |
| parent | c193707dde77ace92a649cd59a17e105e2fbeaef (diff) | |
| download | linux-00b4145298aeb05a2d110117ed18148cb21ebd14.tar.xz | |
ring-buffer: Add interface for setting absolute time stamps
Define a new function, tracing_set_time_stamp_abs(), which can be used
to enable or disable the use of absolute timestamps rather than time
deltas for a trace array.
Only the interface is added here; a subsequent patch will add the
underlying implementation.
Link: http://lkml.kernel.org/r/ce96119de44c7fe0ee44786d15254e9b493040d3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 11 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 33 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 3 |
3 files changed, 46 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index dcf1c4dd3efe..2a03e069bbc6 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -488,6 +488,7 @@ struct ring_buffer { u64 (*clock)(void); struct rb_irq_work irq_work; + bool time_stamp_abs; }; struct ring_buffer_iter { @@ -1382,6 +1383,16 @@ void ring_buffer_set_clock(struct ring_buffer *buffer, buffer->clock = clock; } +void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs) +{ + buffer->time_stamp_abs = abs; +} + +bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer) +{ + return buffer->time_stamp_abs; +} + static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer); static inline unsigned long rb_page_entries(struct buffer_page *bpage) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20a2300ae4e8..cba003f0362e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2269,7 +2269,7 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, *current_rb = trace_file->tr->trace_buffer.buffer; - if ((trace_file->flags & + if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) && (entry = this_cpu_read(trace_buffered_event))) { /* Try to use the per cpu buffer first */ @@ -6282,6 +6282,37 @@ static int tracing_clock_open(struct inode *inode, struct file *file) return ret; } +int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs) +{ + int ret = 0; + + mutex_lock(&trace_types_lock); + + if (abs && tr->time_stamp_abs_ref++) + goto out; + + if (!abs) { + if (WARN_ON_ONCE(!tr->time_stamp_abs_ref)) { + ret = -EINVAL; + goto out; + } + + if (--tr->time_stamp_abs_ref) + goto out; + } + + ring_buffer_set_time_stamp_abs(tr->trace_buffer.buffer, abs); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (tr->max_buffer.buffer) + ring_buffer_set_time_stamp_abs(tr->max_buffer.buffer, abs); +#endif + out: + mutex_unlock(&trace_types_lock); + + return ret; +} + struct ftrace_buffer_info { struct trace_iterator iter; void *spare; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2a6d0325a761..477341710ebf 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -273,6 +273,7 @@ struct trace_array { /* function tracing enabled */ int function_enabled; #endif + int time_stamp_abs_ref; }; enum { @@ -286,6 +287,8 @@ extern struct mutex trace_types_lock; extern int trace_array_get(struct trace_array *tr); extern void trace_array_put(struct trace_array *tr); +extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs); + /* * The global tracer (top) should be the first trace array added, * but we check the flag anyway. |