Date: Wed, 17 Feb 2010 14:13:56 -0500 From: John Baldwin <jhb@freebsd.org> To: freebsd-hackers@freebsd.org Cc: Shrikanth Kamath <shrikanth07@gmail.com> Subject: Re: Ktrace'ing kernel threads Message-ID: <201002171413.56920.jhb@freebsd.org> In-Reply-To: <291941b81002150321w7b0479beo1c6fec39ef6a7922@mail.gmail.com> References: <291941b81002150321w7b0479beo1c6fec39ef6a7922@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Monday 15 February 2010 6:21:40 am Shrikanth Kamath wrote:
> Can ktrace trace another kernel thread which has roughly the semantics as
> below, right now it
> does not hit any of the designated interesting points that ktrace is built
> for, but what if I could define those,
> will ktrace still allow tracing another kernel thread?
>
> thread(client_info)
> {
> ...
> ...
> build_msg(client_info); /* this will malloc a mbuf and fill the data in
> it */
> ...
> sosend(client_info);
> }
>
> I want to time the entry/return of build_msg, and the time sosend, dump
> client_info (some specific fields).
It is probably easier to do this with DTrace (albeit possibly with more
overhead). You can ktrace a kthread fine, but you would need to write your
own ktrace hooks (and record parser for kdump) which would take a bit longer
than a D script with DTrace.
--
John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201002171413.56920.jhb>