Am 19.10.2010 16:29, Richard W.M. Jones wrote: > On Tue, Oct 19, 2010 at 03:59:36PM +0200, Jan Kiszka wrote: >> Once we have "-trace events=...", defining the list of active >> tracepoints before starting qemu will be trivial (e.g. via a config >> file). Of course, this requires that all tracepoints are built-in... > > Sorry that I've not been following this very closely, but does this > sort of thing allow tracing reads and writes to block devices? Am I > right in thinking that if a tracepoint existed in the right place, one > could get a log file from that which could be post-processed in > another tool? > > cf: > http://rwmj.wordpress.com/2010/10/05/visualizing-reads-writes-and-alignment/#content > > Rich. >
Yes. The block layer is instrumented, not sure if already sufficiently, but you may simply want to try the simpletrace backend and inspect the result via its postprocessor (simpletrace.py). Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
