perf test trace: Use --sort-events in BTF general tests

Without the '--sort-events' flag, perf trace doesn't receive and process
events based on their arrival time, thus PERF_RECORD_COMM event that
assigns the correct comm to a PID, may be delivered and processed after
regular samples, causing trace outputs not having a 'comm', e.g.
'mv', instead, having the default PID placeholder, e.g. ':14514'.

Hopefully this answers Namhyung's question in [1].

You can simply justify the statement with this diff: [2].

Now, simply run this command multiple times:
    $ touch /tmp/file1 && sudo /tmp/perf trace -e renameat* -- mv /tmp/file1 /tmp/file2 && rm -f /tmp/file2
And you should see two types of results:

    $ touch /tmp/file1 && sudo /tmp/perf trace -e renameat* -- mv /tmp/file1 /tmp/file2 && rm -f /tmp/file2
    [debug] deliver
    [debug] machine__process_comm_event
    [OVERRIDE] old :1221169 new mv str mv
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
	 0.000 ( 0.013 ms): mv/1221169 renameat2(olddfd: CWD, oldname: "/tmp/file1", newdfd: CWD, newname: "/tmp/file2", flags: NOREPLACE) = 0
    [debug] deliver

    $ touch /tmp/file1 && sudo /tmp/perf trace -e renameat* -- mv /tmp/file1 /tmp/file2 && rm -f /tmp/file2
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
    [debug] deliver
	 0.000 ( 0.014 ms): :1221398/1221398 renameat2(olddfd: CWD, oldname: "/tmp/file1", newdfd: CWD, newname: "/tmp/file2", flags: NOREPLACE) = 0
    [debug] deliver
    [debug] deliver
    [debug] machine__process_comm_event
    [OVERRIDE] old :1221398 new mv str mv
    [debug] deliver
    [debug] deliver
    [debug] deliver

Anyway, use --sort-events in BTF general tests to avoid :PID, a comm is
preferred.

[1]: https://lore.kernel.org/linux-perf-users/[email protected]/
[2]: https://gist.githubusercontent.com/Sberm/6b72b2a1cf1c62244f1f996481769baf/raw/529667bd74a2e7e1953bbd4be545bf875da8a3e7/unsorted.patch

Signed-off-by: Howard Chu <[email protected]>
Tested-by: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

0 files changed, 0 insertions, 0 deletions