linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: "Bu, Yitian" <ybu@qti.qualcomm.com>
Cc: "tglx@linutronix.de" <tglx@linutronix.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"mingo@kernel.org" <mingo@kernel.org>
Subject: Re: [PATCH] Fix rq->lock vs logbuf_lock unlock race
Date: Wed, 20 Feb 2013 11:19:15 +0100	[thread overview]
Message-ID: <1361355555.10155.14.camel@laptop> (raw)
In-Reply-To: <E807E903FE6CBE4D95E420FBFCC273B827522A@nasanexd01h.na.qualcomm.com>

On Wed, 2013-02-20 at 09:38 +0000, Bu, Yitian wrote:
> 
> 2. from printk comment: "This is printk(). It can be called from any
> context. 
> We want it to work. ". I suppose to use printk in any context.

Unfortunately that's not quite possible, rq->lock is really out of
bounds. At one point I tried 'fixing' this but there's a whole bunch of
nasty that's not going to go away.

I've since forgotten most of the details, but aside from logbuf problems
there's a whole host of issues with the console drivers themselves as
well.

If you really want to do this, use early_printk.


  reply	other threads:[~2013-02-20 10:19 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-18 12:53 [PATCH] Fix rq->lock vs logbuf_lock unlock race Bu, Yitian
2013-02-18 14:17 ` [tip:core/printk] printk: Fix rq-> lock vs logbuf_lock unlock lock inversion tip-bot for Bu, Yitian
2013-02-20  8:45 ` [PATCH] Fix rq->lock vs logbuf_lock unlock race Peter Zijlstra
2013-02-20  9:38   ` Bu, Yitian
2013-02-20 10:19     ` Peter Zijlstra [this message]
2013-02-20 11:24       ` Bu, Yitian

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=1361355555.10155.14.camel@laptop \
    --to=a.p.zijlstra@chello.nl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=ybu@qti.qualcomm.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).