From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@oss.sgi.com
Subject: Re: netdev ioctl & dev_base_lock : bad idea ?
Date: Thu, 09 Dec 2004 17:22:13 +1100 [thread overview]
Message-ID: <1102573333.16495.2.camel@gaston> (raw)
In-Reply-To: <20041208220642.6984519f.davem@davemloft.net>
On Wed, 2004-12-08 at 22:06 -0800, David S. Miller wrote:
> On Fri, 26 Nov 2004 19:48:49 +1100
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
>
> > I suppose there is a good reason we can't just use the rtnl_sem for
> > these guys, though why isn't dev_base_lock a read/write semaphore
> > instead of a spinlock ? At least on ppc, I don't think there's any
> > overhead in the normal path, and this is not on a very critical path
> > anyway, is it ?
>
> It can't be a semphore because it is taken in packet processing,
> and thus softint handling, paths.
Right, and I missed the fact that we did indeed take the semaphore and
not the lock in the _set_ functions which is just fine, we can actually
schedule.... except in set_multicast...
Is there any reason we actually _need_ to get the xmit lock in this one
specifically ?
Ben.
next prev parent reply other threads:[~2004-12-09 6:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-26 8:48 netdev ioctl & dev_base_lock : bad idea ? Benjamin Herrenschmidt
2004-12-09 6:06 ` David S. Miller
2004-12-09 6:22 ` Benjamin Herrenschmidt [this message]
2004-12-09 7:13 ` David S. Miller
2004-12-09 22:14 ` Benjamin Herrenschmidt
2004-12-09 23:19 ` David S. Miller
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