From: David Miller <davem@davemloft.net>
To: christophe.leroy@c-s.fr
Cc: linux-kernel@vger.kernel.org, edumazet@google.com,
netdev@vger.kernel.org
Subject: Re: [PATCH] net: optimise csum_replace4()
Date: Fri, 26 Sep 2014 16:14:36 -0400 (EDT) [thread overview]
Message-ID: <20140926.161436.2294622951811354901.davem@davemloft.net> (raw)
In-Reply-To: <20140923085433.09C5A1AB26A@localhost.localdomain>
From: Christophe Leroy <christophe.leroy@c-s.fr>
Date: Tue, 23 Sep 2014 10:54:32 +0200 (CEST)
> csum_partial() is a generic function which is not optimised for small fixed
> length calculations, and its use requires to store "from" and "to" values in
> memory while we already have them available in registers. This also has impact,
> especially on RISC processors. In the same spirit as the change done by
> Eric Dumazet on csum_replace2(), this patch rewrites inet_proto_csum_replace4()
> taking into account RFC1624.
>
> I spotted during a NATted tcp transfert that csum_partial() is one of top 5
> consuming functions (around 8%), and the second user of csum_partial() is
> inet_proto_csum_replace4().
>
> I have proposed the same modification to inet_proto_csum_replace4() in another
> patch.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Applied.
prev parent reply other threads:[~2014-09-26 20:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-23 8:54 [PATCH] net: optimise csum_replace4() Christophe Leroy
2014-09-23 11:08 ` Eric Dumazet
2014-09-26 20:14 ` David Miller [this message]
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