linux-ide.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Justin Piszcz <jpiszcz@lucidpixels.com>,
	linux-kernel@vger.kernel.org, akpm@osdl.org,
	linux-ide@vger.kernel.org, apiszcz@lucidpixels.com
Subject: Re: Linux Kernel 2.6.13-rc7 (WORKS) (2.6.13, DRQ/System CRASH)
Date: Mon, 05 Sep 2005 13:29:57 +0100	[thread overview]
Message-ID: <1125923397.8714.22.camel@localhost.localdomain> (raw)
In-Reply-To: <58cb370e050905002630a0e02e@mail.gmail.com>

On Llu, 2005-09-05 at 09:26 +0200, Bartlomiej Zolnierkiewicz wrote:
> After DMA timeout driver reverted back to PIO,
> ide-taskfile.c also holds PIO code besides IDE Taskfile Access.


On SMP after a DMA timeout it will potentially freeze. There are some
paths in that code which lead to double lock takes and hangs, plus some
timer races.

Justin can you make a backup (I mean that seriously), then build a
kernel with spin lock debug enabled and see if you can reproduce the
problem and get a trace. 

If its the locking you'll get a trace and the kernel will continue. At
that point because the spinlock debug continues unsafely through a
double lock after the trace you are in the "danger zone" hence the
backup warning

[Yes the spin lock debug code really should warn you its dangerous for
non debug uses or get patched as it is in Fedora to trace and stop]

If its a hardware or other problem it will still hang

if its an unrelated lock problem it should still get a trace.


Why you see this only on 2.6.13 not 2.6.13-rc7 I don't know. It makes me
wonder if you have a bad drive - but then you imply going back to rc7
goes back to stable. Can you therefore also check the .config options
between the two kernels match.

Alan

  reply	other threads:[~2005-09-05 12:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-08-31 17:37 Linux Kernel 2.6.13-rc7 (WORKS) (2.6.13, DRQ/System CRASH) Justin Piszcz
2005-08-31 18:09 ` Justin Piszcz
2005-09-05  7:26   ` Bartlomiej Zolnierkiewicz
2005-09-05 12:29     ` Alan Cox [this message]
2005-09-05 17:23       ` Justin Piszcz
2005-09-05  7:32 ` Bartlomiej Zolnierkiewicz

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=1125923397.8714.22.camel@localhost.localdomain \
    --to=alan@lxorguk.ukuu.org.uk \
    --cc=akpm@osdl.org \
    --cc=apiszcz@lucidpixels.com \
    --cc=bzolnier@gmail.com \
    --cc=jpiszcz@lucidpixels.com \
    --cc=linux-ide@vger.kernel.org \
    --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 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).