From: Richard Cochran <richardcochran@gmail.com>
To: Timur Tabi <timur@freescale.com>
Cc: Linuxppc-dev Development <linuxppc-dev@ozlabs.org>
Subject: Re: CONFIG_NO_HZ causing poor console responsiveness
Date: Wed, 30 Jun 2010 08:49:26 +0200 [thread overview]
Message-ID: <20100630064926.GA3792@riccoc20.at.omicron.at> (raw)
In-Reply-To: <AANLkTilMzfwgYvoFhxhcVQVGV-EkMLVHI2TeQ29SYFCH@mail.gmail.com>
On Tue, Jun 29, 2010 at 02:54:17PM -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?
Yes, with a P2020RDB and kernel 2.6.35-rc1. Serial console is really
slow on an otherwise idle machine. I assumed it was a hardware
problem.
Richard
next prev parent reply other threads:[~2010-06-30 5:49 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 [this message]
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
2010-07-02 6:03 ` Li Yang-R58472
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