From: gshan <Gavin.Shan@alcatel-lucent•com>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: linuxppc-dev@lists•ozlabs.org
Subject: Re: spin_lock_irqsave and multi-core
Date: Thu, 01 Apr 2010 11:18:54 +0800 [thread overview]
Message-ID: <4BB4109E.8020607@alcatel-lucent.com> (raw)
In-Reply-To: <1270090589.7101.86.camel@pasglop>
>
> Then your driver is most certainly doing something wrong :-) No driver
> needs that. Ever.
>
> What is it trying to do more precisely ? I might be able to explain what
> the right approach is if you can tell me what the driver is trying to
> disable all system IRQs for ? Keep in mind that local_irq_save() does a
> lot more than just masking external interrupts from your device. It
> masks them from -all- devices, including timer interrupts, perfmon
> interrupts, etc... Doing so on all cores is generally a big no-no and
> almost never really necessary.
>
I agree with you. Actually, I can disable the individual interrupt via
disable_irq_sync() to make sure
system cooherence. It's just my concern when reading kernel source.
Anyway, thanks a lot
for your kindly answer.
Thanks,
Gavin
> Cheers,
> Ben.
>
>
>
next prev parent reply other threads:[~2010-04-01 3:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-01 1:59 spin_lock_irqsave and multi-core gshan
2010-04-01 2:39 ` Benjamin Herrenschmidt
2010-04-01 2:41 ` gshan
2010-04-01 2:56 ` Benjamin Herrenschmidt
2010-04-01 3:18 ` gshan [this message]
2010-04-01 4:45 ` Benjamin Herrenschmidt
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