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| author | Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> | 2020-07-06 18:47:14 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-03-26 13:11:29 -0400 |
| commit | 42347e10aa05b6b0825adccf33a82f21742484ac (patch) | |
| tree | 669995a3e844db977f17b643513d5b308169ffa0 | |
| parent | cd9cf71c1ac1c57037e2749eef210116b9f1ce64 (diff) | |
| download | libtraceevent-42347e10aa05b6b0825adccf33a82f21742484ac.tar.gz | |
tools lib traceveent: Fix kbuffer_start_of_data() to return the first record
The first record in a ring buffer page may not allways be at the
beginning of the page. There could be time-extends injected before it.
In this case kbuffer_start_of_data() will not return the first record,
as expected. Additional field "start" is added in kbuffer struct, to hold
the offset of the first record from the page and kbuffer_start_of_data()
is modified to use it.
Link: https://lore.kernel.org/linux-trace-devel/20200706154714.27566-1-tz.stoyanov@gmail.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Finished the patch from Steven ]
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
| -rw-r--r-- | src/kbuffer-parse.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/kbuffer-parse.c b/src/kbuffer-parse.c index f1640d6..7499950 100644 --- a/src/kbuffer-parse.c +++ b/src/kbuffer-parse.c @@ -35,6 +35,7 @@ enum { * @next - offset from @data to the start of next event * @size - The size of data on @data * @start - The offset from @subbuffer where @data lives + * @first - The offset from @subbuffer where the first non time stamp event lives * * @read_4 - Function to read 4 raw bytes (may swap) * @read_8 - Function to read 8 raw bytes (may swap) @@ -51,6 +52,7 @@ struct kbuffer { unsigned int next; unsigned int size; unsigned int start; + unsigned int first; unsigned int (*read_4)(void *ptr); unsigned long long (*read_8)(void *ptr); @@ -546,6 +548,9 @@ int kbuffer_load_subbuffer(struct kbuffer *kbuf, void *subbuffer) next_event(kbuf); + /* save the first record from the page */ + kbuf->first = kbuf->curr; + return 0; } @@ -756,7 +761,7 @@ void kbuffer_set_old_format(struct kbuffer *kbuf) */ int kbuffer_start_of_data(struct kbuffer *kbuf) { - return kbuf->start; + return kbuf->first + kbuf->start; } /** |