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Date: Tue, 02 Oct 2001 11:22:33 -0700
From: Andrew Morton <akpm@zip.com.au>
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To: Ricky Beam <jfbeam@bluetopia.net>
CC: Lorenzo Allegrucci <lenstra@tiscalinet.it>, linux-kernel@vger.kernel.org
Subject: Re: Huge console switching lags
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Ricky Beam wrote:
> 
> On Tue, 2 Oct 2001, Andrew Morton wrote:
> >In 2.4.10, the console switching code moved from interrupt context
> >into process context.  So if your system is taking a long time to
> >schedule processes (in this case, keventd) then yes, console
> >switching will take a long time.
> 
> And what's the brilliant reason for this?  And don't give any BS about it
> taking too long inside an interrupt context -- we're switching consoles not
> start netscrape.
> 

It takes too long in interrupt context :)  Tens of milliseconds
or more.  More importantly, it sorts the locking out - you can't
acquire a semaphore in interrupt context.
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