From: Jiri Slaby <jslaby@suse.cz>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: Alan Cox <alan@linux.intel.com>,
Al Viro <viro@zeniv.linux.org.uk>,
LKML <linux-kernel@vger.kernel.org>,
Greg KH <gregkh@linuxfoundation.org>
Subject: Re: uart_startup: GFP_KERNEL allocation with IRQs disabled
Date: Fri, 03 Aug 2012 11:37:53 +0200 [thread overview]
Message-ID: <501B9BF1.2050006@suse.cz> (raw)
In-Reply-To: <20120803014600.GA7886@localhost>
On 08/03/2012 03:46 AM, Fengguang Wu wrote:
> Hi all,
Hi,
> The IRQ should be disabled somewhere in the path walk, which makes
> the GFP_KERNEL allocation in uart_startup() no longer valid..
>
> [ 0.499537] kworker/u:1 (29) used greatest stack depth: 7156 bytes left
> [ 0.500947] ------------[ cut here ]------------
> [ 0.501445] WARNING: at /c/kernel-tests/src/stable/kernel/lockdep.c:2739 lockdep_trace_alloc+0x86/0xb2()
> [ 0.502413] Modules linked in:
> [ 0.502766] Pid: 1, comm: init Not tainted 3.5.0-01258-g1ade992 #182
> [ 0.503419] Call Trace:
...
> [ 0.504381] [<c1079e7d>] get_zeroed_page+0xd/0xf
> [ 0.504381] [<c10f976f>] uart_startup.part.8+0x46/0x152
> [ 0.504381] [<c10f745f>] ? tty_port_tty_set+0x37/0x3c
> [ 0.504381] [<c10fa175>] uart_open+0xc9/0x10b
> [ 0.504381] [<c10fa0ac>] ? uart_suspend_port+0x229/0x229
> [ 0.504381] [<c10f1bc2>] tty_open+0x26b/0x3d3
> [ 0.504381] [<c109872a>] chrdev_open+0xf7/0x117
This does not make sense to me. I would not blame TTY/serial for this.
There is somebody who forgot to enable interrupts somewhere. Could you
enable DEBUG_ATOMIC_SLEEP? It might trigger earlier revealing us the
culprit.
thanks,
--
js
suse labs
next prev parent reply other threads:[~2012-08-03 9:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-03 1:46 uart_startup: GFP_KERNEL allocation with IRQs disabled Fengguang Wu
2012-08-03 9:37 ` Jiri Slaby [this message]
2012-08-03 9:51 ` Fengguang Wu
2012-08-03 10:10 ` Al Viro
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=501B9BF1.2050006@suse.cz \
--to=jslaby@suse.cz \
--cc=alan@linux.intel.com \
--cc=fengguang.wu@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/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