From: Ingo Molnar <mingo@elte.hu>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Greg KH <greg@kroah.com>, "Theodore Ts'o" <tytso@mit.edu>,
Linus Torvalds <torvalds@linux-foundation.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: printk() vs tty_io
Date: Wed, 14 Dec 2011 10:46:43 +0100 [thread overview]
Message-ID: <20111214094643.GA8115@elte.hu> (raw)
In-Reply-To: <1323855797.28489.22.camel@twins>
* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2011-12-14 at 07:59 +0100, Ingo Molnar wrote:
>
> > btw., would be nice to also somehow realeasify those debug
> > hacks to preserve them for eternity - doing all lockdep
> > output as earlyprintk while keeping printks working is a
> > great way to debug printk() itself.
> >
> > Those printk lockups also took a *lot* of time for me to
> > bisect.
>
> Yeah, they're horrible.. took me long enough to reproduce, and
> even now I know how its not easy.
>
> Anyway, I just posted the two patches that make lockdep do
> early_printk(), they're not too horrid. [...]
Given how crutial lockdep is to analyzing lockups, i think this
decoupling from printk() innards is a good idea in general.
[ It also rhymes well with the general principles of lockdep, to
create all of its infrastructure from scratch, to be able to
use it everywhere. ]
The small lprintk() ugliness we can live with i think.
Thanks,
Ingo
next prev parent reply other threads:[~2011-12-14 9:48 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-13 19:33 printk() vs tty_io Peter Zijlstra
2011-12-13 23:52 ` Linus Torvalds
2011-12-14 9:38 ` Peter Zijlstra
2011-12-14 10:43 ` Alan Cox
2011-12-14 10:56 ` Peter Zijlstra
2011-12-14 14:05 ` Ted Ts'o
2011-12-14 14:23 ` Peter Zijlstra
2011-12-14 15:54 ` Linus Torvalds
2011-12-15 9:56 ` Peter Zijlstra
2011-12-15 10:32 ` Alan Cox
2011-12-15 10:55 ` Peter Zijlstra
2011-12-15 17:08 ` Linus Torvalds
2011-12-15 18:07 ` Ingo Molnar
2011-12-15 21:22 ` Alan Cox
2011-12-16 13:25 ` Peter Zijlstra
2011-12-15 19:02 ` Greg KH
2011-12-14 6:59 ` Ingo Molnar
2011-12-14 9:40 ` [PATCH] arch, early_printk: Consolidate early_printk() implementations Peter Zijlstra
2011-12-14 9:41 ` [PATCH] lockdep: Enable earlyprintk output Peter Zijlstra
2011-12-14 9:43 ` printk() vs tty_io Peter Zijlstra
2011-12-14 9:46 ` Ingo Molnar [this message]
2011-12-21 12:03 ` Stijn Devriendt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20111214094643.GA8115@elte.hu \
--to=mingo@elte.hu \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=greg@kroah.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=torvalds@linux-foundation.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.