Re: 2.6.14-rc4-rt7

From: Daniel Walker
Date: Tue Oct 18 2005 - 11:23:49 EST


On Tue, 2005-10-18 at 08:42 +0200, Ingo Molnar wrote:
> * Daniel Walker <dwalker@xxxxxxxxxx> wrote:
>
> > I found this latency ~5 minutes after boot up, no load . It looks like
> > vgacon_scroll() has a memset like operation which can grow.
>
> do you have PRINTK_IGNORE_LOGLEVEL enabled? If yes then much of the
> printk code will run with interrupts disabled - hence non-preemptable.
> PRINTK_IGNORE_LOGLEVEL is a debugging feature for developers. I have
> added an extra explanation to the Kconfig, see below.

I was just running a "make defconfig" and I enabled latency tracing .
PRINTK_IGNORE_LOGLEVEL defaults to off (doesn't it?), and I didn't make
any changes to it . Unless it get switched on by something else ..

It looks like the logic might be reversed in release_console_sem() .

Daniel

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