From: Daniel Walker <dwalker@fifo99.com>
To: Mandeep Singh Baines <msb@google.com>
Cc: fweisbec@gmail.com, msb@chromium.org, sshaiju@mvista.com,
mingo@elte.hu, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: hung_task checking and sys_sync
Date: Tue, 12 Jun 2012 15:34:22 -0700 [thread overview]
Message-ID: <20120612223422.GB13492@fifo99.com> (raw)
In-Reply-To: <20120612222912.GB16381@google.com>
On Tue, Jun 12, 2012 at 03:29:12PM -0700, Mandeep Singh Baines wrote:
>
> But the time is not unbounded. You could mask the hung_task_detector for
> this case but then you lose the ability to catch bugs in this code path.
>
> The timeout is configurable via /proc/sys/kernel/hung_task_timeout_secs.
> Can you bump up the value at boot via sysctl.conf?
Maybe, but I'm wondering if these types should just be stopped because Andrew
had complained about them already.
> > Has there been any commit that disable these messages bdi_sched_wait?
> >
>
> No. There is no mechanism to disable hung_task for a specific code path.
> We do skip processes if PF_PROZEN or PF_FROZEN_SKIP is set but that is
> really a different situation where the wait is unbounded.
There is presidence for this type of change,
Author: Mark Lord <kernel@teksavvy.com>
Date: Fri Sep 24 09:51:13 2010 -0400
block: Prevent hang_check firing during long I/O
During long I/O operations, the hang_check timer may fire,
trigger stack dumps that unnecessarily alarm the user.
Eg. hdparm --security-erase NULL /dev/sdb ## can take *hours* to complete
So, if hang_check is armed, we should wake up periodically
to prevent it from triggering. This patch uses a wake-up interval
equal to half the hang_check timer period, which keeps overhead low enough.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
next prev parent reply other threads:[~2012-06-12 22:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-12 22:09 hung_task checking and sys_sync Daniel Walker
2012-06-12 22:29 ` Mandeep Singh Baines
2012-06-12 22:34 ` Daniel Walker [this message]
2012-06-12 22:45 ` Mandeep Baines
2012-06-12 22:57 ` Daniel Walker
2012-06-13 1:03 ` Muthu Kumar
2012-06-13 15:43 ` Daniel Walker
2012-06-13 3:02 ` Sadasivan Shaiju
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=20120612223422.GB13492@fifo99.com \
--to=dwalker@fifo99.com \
--cc=akpm@linux-foundation.org \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=msb@chromium.org \
--cc=msb@google.com \
--cc=sshaiju@mvista.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 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.