From: Andrea Arcangeli <andrea@suse.de>
To: kuznet@ms2.inr.ac.ru
Cc: Dave Miller <davem@redhat.com>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel@vger.kernel.org
Subject: Re: alloc_skb cannot be called with GFP_DMA
Date: Sun, 5 Aug 2001 20:38:10 +0200 [thread overview]
Message-ID: <20010805203810.K21840@athlon.random> (raw)
In-Reply-To: <20010805181606.F21840@athlon.random> <200108051718.VAA17521@ms2.inr.ac.ru>
In-Reply-To: <200108051718.VAA17521@ms2.inr.ac.ru>; from kuznet@ms2.inr.ac.ru on Sun, Aug 05, 2001 at 09:18:11PM +0400
On Sun, Aug 05, 2001 at 09:18:11PM +0400, kuznet@ms2.inr.ac.ru wrote:
> Hello!
>
> > alloc_isa_skb will avoid to slowdown alloc_skb so I prefer it compared
> > to hiding the logic inside alloc_skb.
>
> Stop! This is redundant. GFP_DMA is for skb data, not head!
>
> So that, it is enough and right to clear GFP_DMA inside
> alloc_skb when allocating skb head.
ah it's all metadata, so this should fix it (the bugcheck will still
trap any skb_clone caller that uses GFP_DMA because it doesn't make
sense to call skb_clone with GFP_DMA):
--- 2.4.8pre4aa1/net/core/skbuff.c.~1~ Sat Jul 21 00:04:34 2001
+++ 2.4.8pre4aa1/net/core/skbuff.c Sun Aug 5 20:30:00 2001
@@ -180,7 +180,7 @@
/* Get the HEAD */
skb = skb_head_from_pool();
if (skb == NULL) {
- skb = kmem_cache_alloc(skbuff_head_cache, gfp_mask);
+ skb = kmem_cache_alloc(skbuff_head_cache, gfp_mask & ~__GFP_DMA);
if (skb == NULL)
goto nohead;
}
Andrea
next prev parent reply other threads:[~2001-08-05 18:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-08-05 15:53 alloc_skb cannot be called with GFP_DMA Andrea Arcangeli
2001-08-05 16:03 ` Alan Cox
2001-08-05 16:16 ` Andrea Arcangeli
2001-08-05 17:18 ` kuznet
2001-08-05 18:38 ` Andrea Arcangeli [this message]
2002-09-26 21:18 Manfred Spraul
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