lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sat, 20 Sep 2014 12:30:01 -0400
From:	Steven Rostedt <>
To:	Joe Perches <>
Cc:	Peter Zijlstra <>, Jan Kara <>,
	Markus Trippelsdorf <>,
	Geert Uytterhoeven <>,
	"" <>,
	Andrew Morton <>
Subject: Re: [PATCH] printk: git rid of [sched_delayed] message for

On Sat, 20 Sep 2014 09:10:47 -0700
Joe Perches <> wrote:

> On Sat, 2014-09-20 at 17:47 +0200, Peter Zijlstra wrote:
> > On a whole, printk() is entirely useless for debugging these days, its
> > far too fragile/unreliable to be taken seriously so I really don't care
> > on that point either.
> That's unfortunate.
> Care to enumerate the issues that you believe make
> printk too fragile/unreliable for debugging?

I seldom use printk these days. It's far too limited in its uses. For
one, most things worth debugging happen thousands of times a second,
and printk will just slow things down to a crawl if it is used.
Another, is that it can not be used in most critical sections (NMI
handlers and anything that deals with the scheduler). Also, as it no
longer blocks when another CPU is doing a printk, a bug can happen
which crashes the system and the output of that bug will never get
printed due to the delayed output from another CPU having the console

-- Steve
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists