All of lore.kernel.org
 help / color / mirror / Atom feed
From: Josh Triplett <josh@joshtriplett.org>
To: David Decotigny <decot@googlers.com>
Cc: linux-kernel@vger.kernel.org,
	Ben Hutchings <bhutchings@solarflare.com>,
	"David S. Miller" <davem@davemloft.net>,
	Or Gerlitz <ogerlitz@mellanox.com>,
	Amir Vadai <amirv@mellanox.com>,
	"Paul E. McKenney" <paul.mckenney@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Howells <dhowells@redhat.com>,
	Paul Gortmaker <paul.gortmaker@windriver.com>
Subject: Re: [PATCH v3] lib: cpu_rmap: avoid flushing all workqueues
Date: Sat, 29 Dec 2012 12:36:44 -0800	[thread overview]
Message-ID: <20121229203644.GA31014@leaf> (raw)
In-Reply-To: <796d4768f46d928c68018f44b369df570a0889c4.1356810877.git.decot@googlers.com>

On Sat, Dec 29, 2012 at 11:57:09AM -0800, David Decotigny wrote:
> In some cases, free_irq_cpu_rmap() is called while holding a lock
> (eg. rtnl). This can lead to deadlocks, because it invokes
> flush_scheduled_work() which ends up waiting for whole system
> workqueue to flush, but some pending works might try to acquire the
> lock we are already holding.
> 
> This commit uses reference-counting to replace
> irq_run_affinity_notifiers(). It also removes
> irq_run_affinity_notifiers() altogether.
> 
> Signed-off-by: David Decotigny <decot@googlers.com>

You might consider adding a cpu_rmap_get to parallel cpu_rmap_put.

Also, why keep free_cpu_rmap around at this point?  As far as I can
tell, it has no callers.

Otherwise, this looks good to me.

- Josh Triplett

  reply	other threads:[~2012-12-29 20:36 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1356810877.git.decot@googlers.com>
2012-12-29 19:57 ` [PATCH v3] lib: cpu_rmap: avoid flushing all workqueues David Decotigny
2012-12-29 20:36   ` Josh Triplett [this message]
2013-01-02 20:29     ` Ben Hutchings
2013-01-02 20:34       ` David Decotigny
2013-01-02 21:12         ` David Decotigny
2013-01-02 20:21   ` Ben Hutchings

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=20121229203644.GA31014@leaf \
    --to=josh@joshtriplett.org \
    --cc=akpm@linux-foundation.org \
    --cc=amirv@mellanox.com \
    --cc=bhutchings@solarflare.com \
    --cc=davem@davemloft.net \
    --cc=decot@googlers.com \
    --cc=dhowells@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ogerlitz@mellanox.com \
    --cc=paul.gortmaker@windriver.com \
    --cc=paul.mckenney@linaro.org \
    --cc=tglx@linutronix.de \
    /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.