From: michi1@michaelblizek.twilightparadox.com (michi1 at michaelblizek.twilightparadox.com)
To: kernelnewbies@lists.kernelnewbies.org
Subject: How to measure performance inside Kernel?
Date: Thu, 9 Feb 2012 19:12:24 +0100 [thread overview]
Message-ID: <20120209181223.GA2184@grml> (raw)
In-Reply-To: <CA+MoWDrO0PbKfs=qgzthoEuob2uAirOfhjpdU__GLG34eSaqpw@mail.gmail.com>
Hi!
On 10:58 Thu 09 Feb , Peter Senna Tschudin wrote:
...
> But I want to repeat the tests on specific portion of code, not on
> entire application. Is there a safe way of do something like:
>
> start_bench ( ?? ); /* start measurement */
>
> buf_ptr_end = q->bufs[q->num_buffers];
>
> for (buf_ptr = q->bufs[0]; buf_ptr < buf_ptr_end; ++buf_ptr)
> buf_ptr->state = VB2_BUF_STATE_DEQUEUED;
>
> end_bench ( ?? ); /* end measurement */
Yes, you can do this. If you search for a way for time measurement, take a
look at include/linux/ktime.h .
> And is this the correct approach for testing the performance of
> specific portion of Kernel code?
Why not? I would be a be worried about how the cpu-cache effects the
measurement, especially because your benchmark already showed that a
significant time is spent there.
-Michi
--
programing a layer 3+4 network protocol for mesh networks
see http://michaelblizek.twilightparadox.com
next prev parent reply other threads:[~2012-02-09 18:12 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-09 12:58 How to measure performance inside Kernel? Peter Senna Tschudin
2012-02-09 18:12 ` michi1 at michaelblizek.twilightparadox.com [this message]
2012-02-10 21:47 ` Peter Senna Tschudin
2012-02-10 22:06 ` Jeff Haran
2012-02-11 0:22 ` Peter Senna Tschudin
2012-02-11 3:44 ` Graeme Russ
2012-02-11 13:14 ` Peter Senna Tschudin
2012-02-11 13:57 ` Peter Senna Tschudin
2012-02-12 11:46 ` Mulyadi Santosa
2012-02-13 23:13 ` Peter Senna Tschudin
2012-02-14 3:43 ` Mulyadi Santosa
2012-02-11 7:34 ` michi1 at michaelblizek.twilightparadox.com
2012-02-11 7:22 ` michi1 at michaelblizek.twilightparadox.com
2012-02-11 13:29 ` Peter Senna Tschudin
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