netdev - Re: [PATCH 2/2] tun: fallback if skb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 12 Aug 2008 18:14:09 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Rusty Russell <rusty@...tcorp.com.au>
Cc:	netdev@...r.kernel.org, Max Krasnyansky <maxk@...lcomm.com>
Subject: Re: [PATCH 2/2] tun: fallback if skb_alloc() fails on big packets

On Tue, Aug 12, 2008 at 04:25:53PM +1000, Rusty Russell wrote:
> skb_alloc produces linear packets (using kmalloc()).  That can fail,
> so should we fall back to making paged skbs.
> 
> My original version of this patch always allocate paged skbs for big
> packets.  But that made performance drop from 8.4 seconds to 8.8
> seconds on 1G lguest->Host TCP xmit.  So now we only do that as a
> fallback.
> 
> Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>

I'm not sure that this is really a good idea.  If anything then
tries to expand the head of this skb, they may fail and be forced
to drop the packet.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html