Subject: Re: Preempt? (was Re: Cannot enable DMA on SATA drive
	(SCSI-libsata, VIA SATA))
From: Lee Revell <rlrevell@joe-job.com>
To: Jeff Garzik <jgarzik@pobox.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
       Andrea Arcangeli <andrea@novell.com>, Robert Love <rml@novell.com>,
       Roland Dreier <roland@topspin.com>,
       linux-kernel <linux-kernel@vger.kernel.org>
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On Tue, 2004-10-05 at 23:59, Jeff Garzik wrote:
> The moral of the story is not to use preempt, as it
> * potentially hides long latency code paths
> * potentially introduces bugs, as we've seen with net stack and many 
> other pieces of code
> * is simply not needed, if all code paths are fixed

That's a pretty big if.  If you require low latency now as opposed to
Real Soon Now then preempt is the only option.

Lee

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