On Tue, Mar 25, 2014 at 02:49:42PM +0000, Alex Bennée wrote: > > Stefan Hajnoczi <stefa...@redhat.com> writes: > > > On Mon, Mar 24, 2014 at 05:04:54PM +0000, alex.ben...@linaro.org wrote: > >> From: Alex Bennée <alex.ben...@linaro.org> > >> > >> This makes the UST backend pay attention to the format string arguments > >> that are defined when defining payload data. With this you can now > >> ensure integers are reported in hex mode if you want. > >> > >> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> > >> --- > >> scripts/tracetool/__init__.py | 13 +++++++++++-- > >> scripts/tracetool/backend/ust.py | 16 ++++++++++++---- > >> 2 files changed, 23 insertions(+), 6 deletions(-) > > > > How are strings handled, can LTTng copy them from the QEMU process' > > memory space? > > lttng provides ctf_string for passing strings to the payload. But I > wouldn't expect to use them for the result of format string calculations > as that would defeat the point of the low impact tracing. > > There are a number of trace-events that pass strings for various things. > I've not actually experimented with the output of any of them though.
Sounds like it should work but can you test it? Try enabling the bdrv_open_common() trace event when booting a guest. You should see the filename of the disk image file. Stefan
