From: Andy Gospodarek <andy@greyhouse.net>
To: David Miller <davem@davemloft.net>
Cc: andy@greyhouse.net, jeffrey.t.kirsher@intel.com,
jesse.brandeburg@intel.com, bruce.w.allan@intel.com,
john.ronciak@intel.com, netdev@vger.kernel.org
Subject: Re: [PATCH] igb: completely disable interrupts during netpoll
Date: Wed, 25 Jun 2008 22:49:27 -0400 [thread overview]
Message-ID: <20080626024927.GC32408@gospo.rdu.redhat.com> (raw)
In-Reply-To: <20080625.152751.154176346.davem@davemloft.net>
On Wed, Jun 25, 2008 at 03:27:51PM -0700, David Miller wrote:
> From: Andy Gospodarek <andy@greyhouse.net>
> Date: Wed, 25 Jun 2008 10:15:11 -0400
>
> >
> > Globally disable the interrupt during netpoll rather than simply
> > disabling it on the hardware. This will ensure all pending operations
> > are complete and no more will execute. I've seen reports of deadlocks
> > with the current driver and this patch resolves them.
>
> I don't want to see network drivers start getting into the habit
> of doing this. This operation could be extremely expensive with
> certain IRQ controllers.
>
> It's better to have a good understanding of why the deadlocks
> happen, and this was decidedly missing from your commit message.
>
I thought this was a pretty common problem that cannot simply be solved
with a call to synchronize_irq since you might get one that pops on
another CPU and doesn't set the in-progress bit before your
synchronize_irq call completes?
next prev parent reply other threads:[~2008-06-26 2:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-25 14:15 [PATCH] igb: completely disable interrupts during netpoll Andy Gospodarek
2008-06-25 20:29 ` Brandeburg, Jesse
2008-06-25 20:35 ` Matthew Wilcox
2008-06-25 20:39 ` Andy Gospodarek
2008-06-26 0:29 ` David Miller
2008-06-26 2:40 ` Andy Gospodarek
2008-06-26 2:43 ` David Miller
2008-06-26 18:52 ` Jesse Barnes
2008-06-25 22:27 ` David Miller
2008-06-26 2:49 ` Andy Gospodarek [this message]
2008-06-26 7:23 ` Brandeburg, Jesse
2008-06-26 9:16 ` David Miller
2008-06-26 18:12 ` Andy Gospodarek
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=20080626024927.GC32408@gospo.rdu.redhat.com \
--to=andy@greyhouse.net \
--cc=bruce.w.allan@intel.com \
--cc=davem@davemloft.net \
--cc=jeffrey.t.kirsher@intel.com \
--cc=jesse.brandeburg@intel.com \
--cc=john.ronciak@intel.com \
--cc=netdev@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.