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Date: Thu, 29 Jul 2004 20:04:11 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Lee Revell <rlrevell@joe-job.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
       William Lee Irwin III <wli@holomorphy.com>,
       Lenar L?hmus <lenar@vision.ee>, Andrew Morton <akpm@osdl.org>,
       Arjan van de Ven <arjanv@redhat.com>
Subject: Re: [patch] voluntary-preempt-2.6.8-rc2-L2, preemptable hardirqs
Message-ID: <20040729180411.GA16323@elte.hu>
References: <1090830574.6936.96.camel@mindpipe> <20040726083537.GA24948@elte.hu> <1090832436.6936.105.camel@mindpipe> <20040726124059.GA14005@elte.hu> <20040726204720.GA26561@elte.hu> <20040727162759.GA32548@elte.hu> <1090968457.743.3.camel@mindpipe> <20040728050535.GA14742@elte.hu> <1091051452.791.52.camel@mindpipe> <1091063295.18598.2.camel@mindpipe>
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* Lee Revell <rlrevell@joe-job.com> wrote:

> Here are some more results.  I am up to 56 million interrupts and I
> have yet to trigger a latency higher than 46 usecs.  It looks like
> this is a hard upper limit.

nice - what is the average (and minimum?) latency reported by jackd? 
I'd say 46 usecs on a 600 MHz box is quite close to what it takes to
handle an interrupt and schedule to the cache-cold jackd task. It should
definitely be well below the latency required for jackd to do its job
reliably.

	Ingo