On Wed, 2008-11-19 at 16:07 +0100, Jens Axboe wrote: > On Wed, Nov 19 2008, Martin Peschke wrote: > > On Wed, 2008-11-19 at 13:44 +0100, Jens Axboe wrote: > > > How are you running blktrace? > > > > blktrace -a issue -a drv_data -a complete -w 43200 -o > > - /dev/sda ... /dev/sdz | blkiomon > > Ah ok. How hard is this to reproduce? It's not too hard. I get several bad traces within about half an hour. > If you could try a non-pipe approach, then it would be nice to see if > it happens there as well. I have tried this for about 90 minutes: blktrace -a complete -a issue -a drv_data /dev/sda /dev/sdae /dev/sdaj /dev/sdao /dev/sdat /dev/sday /dev/sdbc /dev/sdbh /dev/sdbm /dev/sdbr /dev/sdbw /dev/sdca /dev/sdg /dev/sdl /dev/sdq /dev/sdv /dev/sdaa No bad traces. Need to check whether verify_trace() was called at all... For this test I had to reduce the number of devices traced due to the oom-killer picking on blktrace. Or did you have something else in mind? > So you don't happen to have a stream of data we can inspect _after_ > the bad magic occured? I was trying with the command line above. Would be blktrace in network mode worth another try? I have just run the my initial test case on a recent linux git tree. Same issue, bad traces: --- bad trace magic --- magic 0x00000000 sequence 0x00000000 time 0x65617407000014d5 <--- first trace magic sector 0x656174070000a75c <--- another trace magic?! bytes 0x0000011e action 0x473dbce5 pid 0x00000000 device 0x0095b5e0 cpu 0x00004000 error 0x0181 pdu_len 0x0008 00000000 00000000 65617407 000014d5 65617407 0000a75c 0000011e 473dbce5 00000000 0095b5e0 00004000 01810008 bad trace in /sys/kernel/debug/block/sdaa/trace0 no previous trace ts->buf 0x0x81fa0610, ts->len 0x958, ts->max_len 0x80000, offset 0x0, t 0x0x81fa0610 Then I ran blkrawverify /dev/sdaa - no issue found. -- To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
