Adding new option to ktrace

[Rajesh S. Ghanekar]

Scott Long wrote:

> Nikhil Dharashivkar wrote:
>
>> Hi,
>>    i want to hack the ktrace system call. Basically, I want to monitor
>> scsi disk IO through dastrategy() routine.
>>     It seems that kern_ktrace.c implements different functions for
>> ktrace options like -tc / -ti ... etc (see man page). So, is it
>> possible to add new option for disk IO with new structure object
>> containing disk io information which will be pass to
>> ktr_submittrequest thr' ktr_request structure.
>>          Will data will be written correctly in ktrace.out and will
>> kdump analyze that ?
>>
>>
>>
>
> What are you trying to monitor?  Would the existing devstat interface
> work?

May be he requires how many bytes transferred (read/write) while a 
process is executing.
I guess devstat doesn't do it from process context, it gives total IO 
read/writes from a device,
if registred via devstat. Please correct me if I am wrong.


- Rajesh

>
> Scott
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