From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <64a6fa23d8a01d86312954ab451692d0@terzarima.net> References: <64a6fa23d8a01d86312954ab451692d0@terzarima.net> Date: Sat, 12 Jun 2010 17:04:06 -0700 Message-ID: From: ron minnich To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=ISO-8859-1 Subject: Re: [9fans] 9vx, kproc and *double sleep* Topicbox-Message-UUID: 31f42aee-ead6-11e9-9d60-3106f5b1d025 On Sat, Jun 12, 2010 at 3:15 PM, Charles Forsyth wrote: >>in Linux parlance, Plan 9 is a "preemptible" kernel. Interrupt handlers can be interrupted, so to speak. > > interrupt handlers are not normally interruptible during the interrupt > processing, but rather at the end (eg, when anyhigher, anyready or preempted > is called). Yes, I was not careful enough in how I said that. For those who wonder what I was trying to say, see trap(); note what happens after the isr() is called and look where preempted() is called. But, all this said, the problems we're seeing on 9vx are strangely similar to the ones I had on Xen when code that was not supposed to be interrupted got interrupted. There may be no real connection at all however. ron