From: Scott Wood <scottwood@freescale.com>
To: Michael Ellerman <michael@ellerman.id.au>
Cc: linuxppc-dev <linuxppc-dev@ozlabs.org>,
Gala Kumar <kumar.gala@freescale.com>,
Li Tony <Tony.Li@freescale.com>
Subject: Re: [PATCH] Add IPIC MSI interrupt support
Date: Tue, 4 Dec 2007 07:13:59 -0600 [thread overview]
Message-ID: <20071204131359.GA5784@loki.buserror.net> (raw)
In-Reply-To: <1196769858.32524.8.camel@concordia>
On Tue, Dec 04, 2007 at 11:04:18PM +1100, Michael Ellerman wrote:
> On Tue, 2007-12-04 at 18:34 +0800, Li Tony wrote:
> > I am not very sure about spin_lock influence.
> > But maybe somebody will change the virq_to_hw implementation.
> > I will take virq_to_hw instead.
>
> I mean the time to take the function call should be pretty small
> compared to taking and releasing a spinlock - but if you have
> performance numbers to prove otherwise let me know :)
I don't think the IPIC is used on any SMP platforms at the moment, so
there's no spinlock overhead other than disabling interrupts...
That said, it's not worth reimplementing to avoid a function call.
-Scott
prev parent reply other threads:[~2007-12-04 13:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-30 3:48 [PATCH] Add IPIC MSI interrupt support Li Li
2007-12-03 1:52 ` David Gibson
2007-12-03 4:59 ` Li Li
2007-12-03 4:02 ` Michael Ellerman
2007-12-03 9:07 ` Li Li
2007-12-03 21:03 ` Benjamin Herrenschmidt
2007-12-04 1:41 ` Li Li
2007-12-04 5:38 ` Michael Ellerman
2007-12-04 7:51 ` Benjamin Herrenschmidt
2007-12-04 9:10 ` Li Li
2007-12-04 10:34 ` Li Tony
2007-12-04 12:04 ` Michael Ellerman
2007-12-04 13:13 ` Scott Wood [this message]
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