On Mon, Jan 30, 2012 at 03:38:57PM +0900, Namhyung Kim wrote: > 2012-01-29 6:41 PM, Namhyung Kim wrote: > >The block_bio_complete() TP has been missed so long, so that bio-based > >drivers haven't been able to trace its IO behavior. Add it. > > > >In some rare cases, such as loop_switch, @bio->bi_bdev can be NULL. > >Thus convert it to TRACE_EVENT_CONDITION() as Steven suggested. > > > > Now I see that it seems TRACE_EVENT_CONDITION() can protect event > tracing from such condition, but what about other users of the TP > like blktrace? I think it'll still get NULL pointer dereference on > bdev_get_queue() after the change, right? If so, convert to T_E_C() > looks meaningless IMHO. Do I miss something? Not really following, but the whole point of using TRACE_EVENT_CONDITION() is avoiding the conditional jump when the TP is disabled. Whether the TP users need to test again / more isn't too important. Thanks. -- tejun -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
