From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net-next] tcp: use TCP_DEFAULT_INIT_RCVWND in tcp_fixup_rcvbuf()
Date: Thu, 20 Oct 2011 22:02:34 +0200 [thread overview]
Message-ID: <1319140954.2854.12.camel@edumazet-laptop> (raw)
In-Reply-To: <20111020.155002.555965434596006787.davem@davemloft.net>
Le jeudi 20 octobre 2011 à 15:50 -0400, David Miller a écrit :
> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Thu, 20 Oct 2011 21:16:26 +0200
>
> > Since commit 356f039822b (TCP: increase default initial receive
> > window.), we allow sender to send 10 (TCP_DEFAULT_INIT_RCVWND) segments.
> >
> > Change tcp_fixup_rcvbuf() to reflect this change, even if no real change
> > is expected, since sysctl_tcp_rmem[1] = 87380 and this value
> > is bigger than tcp_fixup_rcvbuf() computed rcvmem (~23720)
> >
> > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ...
> > + unsigned int mss = min_t(unsigned int, tp->advmss, 1460);
>
> I don't understand where this calculation comes from, and even if it
> should be obvious it isn't to me and deserves a mention in the commit
> message at a minimum.
This is the calculation done in commit 356f039822b as well.
The window is 10*MSS, but no more than 14600
On loopback, this matters, because we could end with rcvmem=219680
next prev parent reply other threads:[~2011-10-20 20:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-20 19:16 [PATCH net-next] tcp: use TCP_DEFAULT_INIT_RCVWND in tcp_fixup_rcvbuf() Eric Dumazet
2011-10-20 19:50 ` David Miller
2011-10-20 20:02 ` Eric Dumazet [this message]
2011-10-20 20:13 ` David Miller
2011-10-20 20:41 ` [PATCH v2 " Eric Dumazet
2011-10-20 20:54 ` David Miller
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