netdev - Re: [PATCH v3 8/7] pppoatm: fix missing wakeup in pppoatm

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Message-ID: <1352581322.9449.109.camel@shinybook.infradead.org>
Date:	Sat, 10 Nov 2012 21:02:02 +0000
From:	David Woodhouse <dwmw2@...radead.org>
To:	Krzysztof Mazur <krzysiek@...lesie.net>
Cc:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Chas Williams - CONTRACTOR <chas@....nrl.navy.mil>,
	davem@...emloft.net
Subject: Re: [PATCH v3 8/7] pppoatm: fix missing wakeup in pppoatm_send()

On Sat, 2012-11-10 at 21:23 +0100, Krzysztof Mazur wrote:
> With this tasklet_schedule() we implement a "spin_lock" here, but in
> this case both conditions (vcc not ready and socket locked) can be
> true for a long time and we can spin here for a long time. I confirmed
> it by reverting patch 1 (atm: detach protocol before closing vcc) and
> now I have 50% of CPU used by ksoftirqd and 50% by pppd (UP system).

Ah, thanks.

Can we take the lock in the tasklet, so we wait for it instead of
spinning?

-- 
dwmw2


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