From: bernd@petrovitsch.priv.at (Bernd Petrovitsch)
To: kernelnewbies@lists.kernelnewbies.org
Subject: How can I 'getchar()' in module code?
Date: Tue, 03 Dec 2013 15:20:55 +0100 [thread overview]
Message-ID: <1386080455.9055.28.camel@thorin> (raw)
In-Reply-To: <44408.1386077884@turing-police.cc.vt.edu>
On Die, 2013-12-03 at 08:38 -0500, Valdis.Kletnieks at vt.edu wrote:
> On Tue, 03 Dec 2013 20:35:41 +0800, said:
> > For debugging purpose, I want something like 'getchar()' that can pause
> > execution in the module code. Do any candidates I can choose?
You do not want that - there is way too much parallelism and
asynchronous stuff in the kernel.
Debugging with getchar() and the like pretty much works only in
single-threaded stuff ....
> The problem is that pausing execution in module code is dangerous, as if
> you hold any locks or anything like that, you can hang other threads or
> even the whole machine.
>
> You probablhy want to be looking at the kgdb support, that is coded to
> work around a lot of the issues and you get full GDB support not just a
> getchar() pause.
Or just use printk() to print interesting values in interesting cases.
Bernd
--
Bernd Petrovitsch Email : bernd at petrovitsch.priv.at
LUGA : http://www.luga.at
next prev parent reply other threads:[~2013-12-03 14:20 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-03 12:35 How can I 'getchar()' in module code? 乃宏周
2013-12-03 13:20 ` Daniel Baluta
2013-12-03 13:38 ` Valdis.Kletnieks at vt.edu
2013-12-03 14:20 ` Bernd Petrovitsch [this message]
2013-12-04 21:21 ` Daniel Baluta
2013-12-05 13:14 ` Bernd Petrovitsch
2013-12-05 1:34 ` Peter Teoh
2013-12-05 4:45 ` 乃宏周
2013-12-06 1:40 ` Fan Du
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