From: David Miller <davem@davemloft.net>
To: zbr@ioremap.net
Cc: ilpo.jarvinen@helsinki.fi, netdev@vger.kernel.org, efault@gmx.de,
mingo@elte.hu, a.p.zijlstra@chello.nl,
herbert@gondor.apana.org.au
Subject: Re: tbench wrt. loopback TSO
Date: Mon, 27 Oct 2008 12:37:17 -0700 (PDT) [thread overview]
Message-ID: <20081027.123717.71252945.davem@davemloft.net> (raw)
In-Reply-To: <20081027193502.GA2590@ioremap.net>
From: Evgeniy Polyakov <zbr@ioremap.net>
Date: Mon, 27 Oct 2008 22:35:02 +0300
> On Mon, Oct 27, 2008 at 11:39:04AM -0700, David Miller (davem@davemloft.net) wrote:
> > One idea immediately occurs to me. Since we're effectively limited
> > to a 64K TSO frame, and the MSS is some value smaller than that, we
> > can probably get away with a reciprocol divide. Even using a 16-bit
> > inverse value would suffice, so we wouldn't need to use u64's like
> > some other pieces of code do. A u32 would be enough.
>
> But why do we need to trim that last bytes at the first place at all?
> Is it just enough to 'binary and' with 0xffff? Or is it what you mean? :)
We need to trim because we want to send full sized frames onto the
network, and those trailing bytes will make sub-MSS sized frame
instead of coalescing with the next round of user sendmsg() data.
next prev parent reply other threads:[~2008-10-27 19:37 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-16 0:14 tbench wrt. loopback TSO David Miller
2008-10-17 3:49 ` non-TCP tbench (was Re: tbench wrt. loopback TSO) David Miller
2008-10-26 12:34 ` tbench wrt. loopback TSO Evgeniy Polyakov
2008-10-27 1:59 ` David Miller
2008-10-27 7:49 ` Ilpo Järvinen
2008-10-27 14:13 ` Evgeniy Polyakov
2008-10-27 15:19 ` Ilpo Järvinen
2008-10-27 17:03 ` Evgeniy Polyakov
2008-10-27 18:39 ` David Miller
2008-10-27 19:35 ` Evgeniy Polyakov
2008-10-27 19:37 ` David Miller [this message]
2008-11-05 11:42 ` David Miller
2008-11-05 11:49 ` Evgeniy Polyakov
2008-11-05 11:54 ` David Miller
2008-11-05 12:04 ` Ilpo Järvinen
2008-11-05 12:09 ` David Miller
2008-11-05 12:25 ` Ilpo Järvinen
2008-11-05 13:04 ` Evgeniy Polyakov
2008-11-05 13:33 ` Ilpo Järvinen
2008-11-05 18:48 ` Rick Jones
2008-11-05 19:46 ` Ilpo Järvinen
2008-11-05 21:06 ` Rick Jones
2008-10-27 22:17 ` Ilpo Järvinen
2008-10-31 8:14 ` David Miller
2008-10-31 9:16 ` Ilpo Järvinen
2008-10-31 9:47 ` David Miller
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