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authorSteven Rostedt (Red Hat) <srostedt@redhat.com>2013-03-05 09:24:35 -0500
committerSteven Rostedt <rostedt@goodmis.org>2013-03-15 00:35:40 -0400
commit12883efb670c28dff57dcd7f4f995a1ffe153b2d (patch)
tree36dcb1c14aaf7afb6515ce9230a75d0602c7fab1 /include
parent22cffc2bb4a50d8c56f03c56f9f19dea85b78e30 (diff)
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tracing: Consolidate max_tr into main trace_array structure
Currently, the way the latency tracers and snapshot feature works is to have a separate trace_array called "max_tr" that holds the snapshot buffer. For latency tracers, this snapshot buffer is used to swap the running buffer with this buffer to save the current max latency. The only items needed for the max_tr is really just a copy of the buffer itself, the per_cpu data pointers, the time_start timestamp that states when the max latency was triggered, and the cpu that the max latency was triggered on. All other fields in trace_array are unused by the max_tr, making the max_tr mostly bloat. This change removes the max_tr completely, and adds a new structure called trace_buffer, that holds the buffer pointer, the per_cpu data pointers, the time_start timestamp, and the cpu where the latency occurred. The trace_array, now has two trace_buffers, one for the normal trace and one for the max trace or snapshot. By doing this, not only do we remove the bloat from the max_trace but the instances of traces can now use their own snapshot feature and not have just the top level global_trace have the snapshot feature and latency tracers for itself. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ftrace_event.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index d6964244e567..d84c4a575514 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -8,6 +8,7 @@
#include <linux/perf_event.h>
struct trace_array;
+struct trace_buffer;
struct tracer;
struct dentry;
@@ -67,6 +68,7 @@ struct trace_entry {
struct trace_iterator {
struct trace_array *tr;
struct tracer *trace;
+ struct trace_buffer *trace_buffer;
void *private;
int cpu_file;
struct mutex mutex;