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From: Tejun Heo <tj@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>, Sitsofe Wheeler <sitsofe@yahoo.com>,
	Borislav Petkov <bp@alien8.de>, Meelis Roos <mroos@linux.ee>,
	Andrew Morton <akpm@linux-foundation.org>,
	Kay Sievers <kay.sievers@vrfy.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH RESEND 2/3 v2.6.39-rc7] block: make disk_block_events() properly wait for work cancellation
Date: Wed, 18 May 2011 07:07:29 +0200	[thread overview]
Message-ID: <20110518050729.GA16870@mtj.dyndns.org> (raw)
In-Reply-To: <BANLkTi=-Ak5vhCFxgc2rt2rft0PE9XJiTA@mail.gmail.com>

On Tue, May 17, 2011 at 03:40:11PM -0700, Linus Torvalds wrote:
> On Tue, May 17, 2011 at 8:27 AM, Tejun Heo <tj@kernel.org> wrote:
> >
> > Spinlock inside mutex seemed a bit strange but yeah that probably is
> > the simpliest way.
> 
> Do you really even need the spinlock at all?

There were sites which called disk_unblock/check_events() with
bdevlock held, which was why it was made spinlock in the first place.
Hmmm... they're not there anymore.

> Just make the semaphore protect the count - and you're done.

Yeah, with that gone, we don't even need the open-coding inside
disk_check_events().  It can simply call syncing block and unblock.
But, do you want that in -rc7?  Unnecessarily complicated as the
current code may be, converting the lock to mutex is a larger change
than adding an outer mutex and I think it would be better to do that
during the next cycle.

Thanks.

--
tejun

  reply	other threads:[~2011-05-18  5:07 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-17 10:27 [PATCH RESEND 1/3 v2.6.39-rc7] block: don't use non-syncing event blocking in disk_check_events() Tejun Heo
2011-05-17 10:28 ` [PATCH RESEND 2/3 v2.6.39-rc7] block: remove non-syncing __disk_block_events() and fold it into disk_block_events() Tejun Heo
2011-05-17 10:28   ` [PATCH RESEND 2/3 v2.6.39-rc7] block: make disk_block_events() properly wait for work cancellation Tejun Heo
2011-05-17 14:46     ` Linus Torvalds
2011-05-17 15:11       ` Tejun Heo
2011-05-17 15:15         ` Linus Torvalds
2011-05-17 15:27           ` Tejun Heo
2011-05-17 22:40             ` Linus Torvalds
2011-05-18  5:07               ` Tejun Heo [this message]
2011-05-18  9:46                 ` Linus Torvalds
2011-05-18 10:04                   ` Tejun Heo
2011-05-18 11:07                     ` Tejun Heo
2011-05-18 10:26                   ` Jens Axboe
2011-05-17 15:47     ` [PATCH UPDATED " Tejun Heo
2011-05-17 19:34       ` Jens Axboe
2011-05-17 20:22         ` Borislav Petkov

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