On Mon, Sep 11, 2017 at 8:16 AM, Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> wrote: > On Fri, Sep 08, 2017 at 03:21:53PM -0600, Ross Zwisler wrote: >> This adds a regression test for the following kernel patch: >> >> xfs: always use DAX if mount option is used >> >> This test will also pass with kernel v4.14-rc1 and beyond because the XFS >> DAX I/O mount option has been disabled (but not removed), so the >> "chattr -x" to turn off DAX doesn't actually do anything. >> >> Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> >> Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> > > <> > >> +# disable tracing, clear the existing trace buffer and turn on dax tracepoints >> +echo 0 > /sys/kernel/debug/tracing/tracing_on >> +echo > /sys/kernel/debug/tracing/trace >> +echo 1 > /sys/kernel/debug/tracing/events/fs_dax/enable > > I think I can do a better job of: > > a) detecting whether debugfs is present, and if not just bail the test as not > run > > b) recording the current state of the debugfs (tracing_on, fs_dax/enable), > doing what I need to do, then restoring the previous state. > > Before I work on a v2, though, I'd love to get feedback on whether or not > using tracepoints is okay in fstests. I think it is more straightforward to use "perf record -e fs_dax $test". Then you know the events are filtered to your test pid and you don't need to worry about managing the trace interface. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
