From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tao Ma Date: Thu, 07 Jul 2011 09:53:05 +0000 Subject: Re: blktrace on my block device Message-Id: <4E158201.3020907@tao.ma> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-btrace@vger.kernel.org On 07/07/2011 05:41 PM, Gangadhar Mylapuram wrote: > Hi, > > As for my understanding I no need to handle (BLKRESTART, BLKTRACESTOP, > BLKTRACESETUP ..) in my device ioctl handling. It is block l/O layer > which intercepts the > statistics and does the job. > > But for my device (not sda or hda), blktrace only show the Q events. > It is not showing even C (completed) events. Do I need to add the > support in my device ioctl handling code? These trace pointers are only recorded if they are met. So I guess the reason is that your device implements your own make_request_fn(So you can see 'Q' event) and no other trace point is met at all. Thanks, Tao