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From: Benjamin Herrenschmidt <benh@kernel•crashing.org>
To: Timur Tabi <timur@freescale•com>
Cc: Linuxppc-dev Development <linuxppc-dev@ozlabs•org>
Subject: Re: CONFIG_NO_HZ causing poor console responsiveness
Date: Fri, 02 Jul 2010 15:47:24 +1000	[thread overview]
Message-ID: <1278049644.4200.377.camel@pasglop> (raw)
In-Reply-To: <AANLkTilMzfwgYvoFhxhcVQVGV-EkMLVHI2TeQ29SYFCH@mail.gmail.com>

On Tue, 2010-06-29 at 14:54 -0500, Timur Tabi wrote:
> I'm adding support for a new e500-based board (the P1022DS), and in
> the process I've discovered that enabling CONFIG_NO_HZ (Tickless
> System / Dynamic Ticks) causes significant responsiveness problems on
> the serial console.  When I type on the console, I see delays of up to
> a half-second for almost every character.  It acts as if there's a
> background process eating all the CPU.
> 
> I don't have time to debug this thoroughly at the moment.  The problem
> occurs in the latest kernel, but it appears not to occur in 2.6.32.
> 
> Has anyone else seen anything like this?

I noticed that on the bimini with 2.6.35-rc* though I didn't get to
track it down yet.

Cheers,
Ben.

  parent reply	other threads:[~2010-07-02  5:47 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-29 19:54 CONFIG_NO_HZ causing poor console responsiveness Timur Tabi
2010-06-30  6:49 ` Richard Cochran
2010-07-01 21:55 ` Timur Tabi
2010-07-02  3:46   ` Mike Galbraith
2010-07-02  3:54     ` Tabi Timur-B04825
2010-07-02  5:47 ` Benjamin Herrenschmidt [this message]
2010-07-02  6:03   ` Li Yang-R58472

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