[RFC PATCH 3/4] trace: Duplicate the output of the function trace logs to STM
From: alexander.shishkin@linux.intel.com (Alexander Shishkin)
Date: 2016-06-07 10:00:27
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lkml
Chunyan Zhang [off-list ref] writes:
This patch adds an output from Ftrace to STM.
But does it?
That being said, Function trace messages would also be duplicated to STM buffer when being stored into ring buffer.
Not sure what you mean here. What's "STM buffer"?
quoted hunk ↗ jump to hunk
Signed-off-by: Chunyan Zhang <redacted> --- kernel/trace/trace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8a4bd6b..d613053 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c@@ -44,6 +44,7 @@ #include "trace.h" #include "trace_output.h" +#include "trace_output_stm.h" /* * On boot up, the ring buffer is set to the minimum size, so that@@ -1884,8 +1885,10 @@ trace_function(struct trace_array *tr, entry->ip = ip; entry->parent_ip = parent_ip; - if (!call_filter_check_discard(call, entry, buffer, event)) + if (!call_filter_check_discard(call, entry, buffer, event)) { __buffer_unlock_commit(buffer, event); + ftrace_stm_func(ip, parent_ip); + }
So this logs instruction pointers, not the actual events. Not much is duplicated like the message suggests, but it also doesn't seem very useful. Regards, -- Alex