From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Paul Fulghum <paulkf@microgate.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH] TTY flip buffer SMP changes
Date: Fri, 08 Oct 2004 13:51:36 +0100 [thread overview]
Message-ID: <1097239894.2290.13.camel@localhost.localdomain> (raw)
In-Reply-To: <1097242506.2008.30.camel@deimos.microgate.com>
On Gwe, 2004-10-08 at 14:35, Paul Fulghum wrote:
> It does seem to carry serious overhead (in relation
> to ring buffers) for devices with small FIFOs.
Thats one reason I wanted sk_buff like rather than sk_buff. I want
to be able to recycle buffers back to drivers when the driver thinks
its the right thing to do.
Then you get something like
next_buffer()
{
new_buf = tty->nextbuf;
if(!new_buf)
new_buf = grow_tty_buf(tty);
queue_to_ldisc(tty->buf);
tty->buf = newbuf;
}
and "free" most of the time can simply queue the buffer back to the tty.
That degenerates into flip buffers in good conditions..
> to the line discipline. This amounts to ~3600 sk_buff
> allocations per second at 115200bps.
Ethernet packets at 1500bytes arriving at 100Mbit is rather higher than
that, and the processing demands are higher too
next prev parent reply other threads:[~2004-10-08 13:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-07 19:58 [RFC][PATCH] TTY flip buffer SMP changes Paul Fulghum
2004-10-07 19:37 ` Alan Cox
2004-10-08 6:26 ` Theodore Ts'o
2004-10-08 13:35 ` Paul Fulghum
2004-10-08 12:51 ` Alan Cox [this message]
2004-10-08 15:00 ` Theodore Ts'o
2004-10-09 1:42 ` Benjamin Herrenschmidt
2004-10-10 0:32 ` Alan Cox
2004-10-10 3:26 ` Benjamin Herrenschmidt
2004-10-10 12:49 ` Maciej W. Rozycki
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