From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: gshan <Gavin.Shan@alcatel-lucent.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: spin_lock_irqsave and multi-core
Date: Thu, 01 Apr 2010 13:56:29 +1100 [thread overview]
Message-ID: <1270090589.7101.86.camel@pasglop> (raw)
In-Reply-To: <4BB407F6.3070106@alcatel-lucent.com>
On Thu, 2010-04-01 at 10:41 +0800, gshan wrote:
> One of my private driver need it. I don't know how to do it.
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.
Cheers,
Ben.
next prev parent reply other threads:[~2010-04-01 2:56 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 [this message]
2010-04-01 3:18 ` gshan
2010-04-01 4:45 ` Benjamin Herrenschmidt
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