Messages in this thread | | | Date | Mon, 13 Apr 2009 15:28:52 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] blktrace: move trace/ dir to /sys/block/sda/ |
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Em Mon, Apr 13, 2009 at 08:00:54PM +0200, Jens Axboe escreveu: > On Mon, Apr 13 2009, Li Zefan wrote: > > Impact: allow ftrace-plugin blktrace to trace device-mapper devices > > > > blktrace can't trace a single partition, so it makes no sense to > > have one trace/ dir in each /sys/block/sda/sdaX. Move it to > > /sys/block/sda/. > > > > Thus we fix an issue reported by Ted, that ftrace-plugin blktrace > > can't be used to trace device-mapper devices. > > Perhaps I never committed that patch, but it would be trivial to do > partition based blktrace tracing. It's also quite useful. So please > don't go changing things to make that harder to support, it would be > nicer to just add the (small) bits to support per-partition tracing. > It's basically just a start/stop sector range, while some events are > per-device and should just be included always.
I was a bit skeptical about this one as well, the fact that partition based tracing was not available annoyed me, but as I was concentrating just on getting the ftrace plugin merged and not on actually improving what was there before... Anyway, will continue listening to these discussions, blktrace was such a early champion for kernel tracing infrastructure that it _has_ to be studied properly in light of current tracing woodstock 8-)
- Arnaldo
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