From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Daniel Walker <dwalker@mvista.com>
Cc: akpm@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm] console: console_drivers not initialized
Date: Mon, 25 Sep 2006 22:30:31 +0100 [thread overview]
Message-ID: <20060925213031.GD25257@flint.arm.linux.org.uk> (raw)
In-Reply-To: <1159219581.3648.10.camel@c-67-180-230-165.hsd1.ca.comcast.net>
On Mon, Sep 25, 2006 at 02:26:21PM -0700, Daniel Walker wrote:
> On Mon, 2006-09-25 at 22:11 +0100, Russell King wrote:
> > On Mon, Sep 25, 2006 at 02:07:10PM -0700, dwalker@mvista.com wrote:
> > > I was doing -rt stuff on a PPC PowerBook G4. It would always reboot
> > > itself when it hit console_init() .
> > >
> > > I noticed that the console code seems to want console_drivers = NULL,
> > > but it never actually sets it that way. Once I added this, the reboot
> > > issue was gone..
> >
> > It's a BSS variable, it _should_ be zeroed by the architecture's BSS
> > initialisation. If not, it suggests there's something very _very_
> > wrong in the architecture's C runtime initialisation code.
> >
> > As such, this patch is merely a band-aid, not a correct fix.
>
> It happens on two different compilers gcc 4.1 and 3.3 ..
The zeroing of the BSS is not a function of the compiler, but the C startup
code, which might be written in assembly or c.
> I was using
> arch/powerpc/ which is fairly new .. However, If stuff was suppose to be
> zero'd and wasn't, I'd imagine this machine would be rebooting _a lot_
> more often.
The alternative explaination is that explicitly changing a variable from
the BSS to have an explicit initialisation moves it into the data segment,
which results in quite a bit of data moving around. So it might not even
be related to this - maybe a data structure alignment issue somewhere?
Shrug - but it's for powerpc folk to investigate.
Suggest you report it to powerpc folk as a bug.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
next prev parent reply other threads:[~2006-09-25 21:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-25 21:07 [PATCH -mm] console: console_drivers not initialized dwalker
2006-09-25 21:11 ` Russell King
2006-09-25 21:26 ` Daniel Walker
2006-09-25 21:30 ` Russell King [this message]
2006-09-25 21:42 ` Andrew Morton
2006-09-26 5:13 ` Paul Mackerras
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=20060925213031.GD25257@flint.arm.linux.org.uk \
--to=rmk+lkml@arm.linux.org.uk \
--cc=akpm@osdl.org \
--cc=dwalker@mvista.com \
--cc=linux-kernel@vger.kernel.org \
/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.