Date: Thu, 02 May 2002 14:00:27 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: Terry Lambert <tlambert2@mindspring.com> Cc: Jonathan Mini <mini@FreeBSD.org>, Andrew Gallatin <gallatin@cs.duke.edu>, freebsd-smp@FreeBSD.org Subject: Re: hlt when idle? Message-ID: <XFMail.20020502140027.jhb@FreeBSD.org> In-Reply-To: <3CD1780B.2CC97DDB@mindspring.com>
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On 02-May-2002 Terry Lambert wrote: > I think the confusion is because it's useful for the clock to > be broadcast for one set of reasons, and it's useful to hit on > only one processor for global handler processing for another > set of reasons. Err, some confusion may be that in current we have two different types of clock interrupt handlers. :) For example, for hardclock, we ahve hardclock() and hardclock_process(). We call hardclock() on only one CPU, and hardclock_process() on all the others. hardclock() does system-wide global changes and then runs the thread-specific hardclock_process(). hardclock_process() does thread-specific things like setting up SIGVTALRM and SIGPROF. Currently hardclock_process() (and even more-so, statclock_process()) use the global sched_lock, thus broadcast doesn't reduce contention unless it is a staggered broadcast. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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