From: Ingo Molnar <mingo@elte.hu>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mike Galbraith <efault@gmx.de>, Robert Swan <swan.r.l@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [bisected] pty performance problem
Date: Mon, 23 Nov 2009 13:04:09 +0100 [thread overview]
Message-ID: <20091123120409.GA32009@elte.hu> (raw)
In-Reply-To: <20091123115949.29bcf89d@lxorguk.ukuu.org.uk>
* Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> > > Another possibility is to do
> > >
> > > if (tty->low_latency)
> > > schedule_delayed_work(&tty->buf.work, 0);
> > > else
> > > schedule_delayed_work(&tty->buf.work, 1);
> >
> > Flaggery for low latency is kind of lame though - especially if it
> > defaults to off in most drivers as you say.
>
> So you'd prefer to detect devices that are byte based or message based
> by what method ?
I'd not delay the worklet by default - i.e. i'd do Mike's patch.
Havent tested all effects of it though - do you have any estimation
about negative effects from such a change? We do have hard numbers
(latencies in the millisecs range) from the opposite direction and those
numbers arent pretty.
Ingo
next prev parent reply other threads:[~2009-11-23 12:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-21 22:23 Robert Swan
2009-11-21 23:23 ` Alan Cox
2009-11-22 0:27 ` Robert Swan
2009-11-22 12:29 ` Alan Cox
2009-11-22 12:41 ` Mike Galbraith
2009-11-22 21:37 ` Robert Swan
2009-11-22 6:39 ` Ingo Molnar
2009-11-22 7:15 ` Arjan van de Ven
2009-11-22 21:56 ` Robert Swan
2009-11-22 12:23 ` Alan Cox
2009-11-22 12:42 ` Ingo Molnar
2009-11-23 5:00 ` Mike Galbraith
2009-11-23 10:28 ` Alan Cox
2009-11-23 11:31 ` Alan Cox
2009-11-23 11:48 ` Ingo Molnar
2009-11-23 11:59 ` Alan Cox
2009-11-23 12:04 ` Ingo Molnar [this message]
2009-11-23 13:34 ` Alan Cox
2009-11-23 17:48 ` Ingo Molnar
2011-07-09 6:29 ` Robert Swan
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