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| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2018-01-15 20:51:39 -0600 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-03-10 16:05:50 -0500 |
| commit | 00b4145298aeb05a2d110117ed18148cb21ebd14 (patch) | |
| tree | 610810c0d71a584fe63b555d07dafba619ab8054 /kernel/trace/trace.c | |
| parent | c193707dde77ace92a649cd59a17e105e2fbeaef (diff) | |
| download | linux-rt-00b4145298aeb05a2d110117ed18148cb21ebd14.tar.gz | |
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/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 33 |
1 files changed, 32 insertions, 1 deletions
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; |