From: Andi Kleen <ak@muc.de>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@oss.sgi.com
Subject: Re: Locking model for NAPI drivers
Date: Wed, 01 Jun 2005 08:28:04 +0200 [thread overview]
Message-ID: <m1fyw2wpzf.fsf@muc.de> (raw)
In-Reply-To: <20050531.154847.63995530.davem@davemloft.net> (David S. Miller's message of "Tue, 31 May 2005 15:48:47 -0700 (PDT)")
"David S. Miller" <davem@davemloft.net> writes:
Stupid question, but...
> I was doing some brainstorming to try and fix a nagging problem in
> the tg3 driver which suggested that doing the SMP locking differently
> might be the best and cleanest solution.
>
> The tg3 problem is that it can do an skb_copy() in HW IRQ disabled
> context which is illegal.
That is because of the kmap_atomic it does right? At least in the i386
highmem implementation I don't see any code that would be less safe in
hard interrupt context compared to BHs. And FRV and mips look like they
allow it too.
> This fixes the skb_copy() we were doing with hw
> IRQs disabled (which is illegal and triggers a
> BUG() with HIGHMEM enabled).
Which BUG did it trigger?
-Andi
next prev parent reply other threads:[~2005-06-01 6:28 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-31 22:48 Locking model for NAPI drivers David S. Miller
2005-06-01 6:28 ` Andi Kleen [this message]
2005-06-01 8:42 ` Herbert Xu
2005-06-01 8:16 ` Greg Banks
2005-06-01 20:33 ` Michael Chan
2005-06-01 22:21 ` David S. Miller
2005-06-01 21:34 ` Michael Chan
2005-06-02 19:56 ` Michael Chan
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