From owner-freebsd-smp Mon Jul 3 16:48: 5 2000 Delivered-To: freebsd-smp@freebsd.org Received: from mailhost.iprg.nokia.com (mailhost.iprg.nokia.com [205.226.5.12]) by hub.freebsd.org (Postfix) with ESMTP id 4F90337BA9D for ; Mon, 3 Jul 2000 16:48:01 -0700 (PDT) (envelope-from jre@iprg.nokia.com) Received: from darkstar.iprg.nokia.com (darkstar.iprg.nokia.com [205.226.5.69]) by mailhost.iprg.nokia.com (8.9.3/8.9.3-GLGS) with ESMTP id QAA17821; Mon, 3 Jul 2000 16:47:59 -0700 (PDT) Received: (from mail@localhost) by darkstar.iprg.nokia.com (8.9.3/8.9.3-VIRSCAN) id QAA05600; Mon, 3 Jul 2000 16:47:57 -0700 X-Virus-Scanned: Mon, 3 Jul 2000 16:47:57 -0700 Nokia Silicon Valley Email Exploit Scanner Received: from UNKNOWN (205.226.1.150, claiming to be "iprg.nokia.com") by darkstar with SMTP id smtpdoKR9wT; Mon, 03 Jul 2000 16:47:52 PDT Message-ID: <39612626.3E3AE2C4@iprg.nokia.com> Date: Mon, 03 Jul 2000 16:47:51 -0700 From: Joe Eykholt Organization: Nokia IPRG X-Mailer: Mozilla 4.7 [en] (X11; I; FreeBSD 2.2.6-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: Greg Lehey Cc: "Jeroen C. van Gelderen" , Daniel Eischen , Jason Evans , Luoqi Chen , smp@FreeBSD.ORG Subject: Re: SMP meeting summary References: <20000703114535.T39024@wantadilla.lemis.com> <20000703200039.H62680@wantadilla.lemis.com> <3960A971.982DDF07@vangelderen.org> <20000704083822.A65029@wantadilla.lemis.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Greg Lehey wrote: > There's nothing to say that wake_one is more complex. wake_one takes > the first process on the mutex's sleep list and wakes it. wake_all > (or whatever) would make a loop out of that wake function and wake all > the processes on the list. All would then be scheduled, try to take > the mutex, and all except one would fail and be put back on the sleep > list. Does this make sense? With adaptive mutexes, the threads which are woken will either run one serially on one CPU, or some run at the same time on multiple CPUs. In that case, one gets the lock right away, and the rest SPIN on it (as long as the new owner doesn't get suspended on something else). They don't necessarily go back to sleep on that same lock. I agree it's too early to talk about this degree of optimization, though. Joe Eykholt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message