From owner-freebsd-smp Tue Apr 24 10:58:50 2001 Delivered-To: freebsd-smp@freebsd.org Received: from mx.databus.com (p101-44.acedsl.com [160.79.101.44]) by hub.freebsd.org (Postfix) with ESMTP id B6F1F37B423; Tue, 24 Apr 2001 10:58:47 -0700 (PDT) (envelope-from barney@mx.databus.com) Received: (from barney@localhost) by mx.databus.com (8.11.3/8.11.3) id f3OHwjJ10357; Tue, 24 Apr 2001 13:58:45 -0400 (EDT) (envelope-from barney) Date: Tue, 24 Apr 2001 13:58:45 -0400 From: Barney Wolff To: "Andrew R. Reiter" Cc: Robert Watson , John Baldwin , smp@FreeBSD.ORG Subject: Re: sysctl's and mutexes Message-ID: <20010424135845.A10320@mx.databus.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: ; from arr@watson.org on Tue, Apr 24, 2001 at 01:47:17PM -0400 Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Pardon an outsider's question, but what exactly are these mutex's supposed to protect? Would a reader of a sysctl value have to acquire a read lock in order to read a non-atomic value? Is the rate at which these values are set and/or read so high as to justify more than a single mutex for the lot? Are there any operations that take long enough that anything other than a spinlock is justified? Sorry if these are dumb questions - I'm just a KISS sort of guy. Barney Wolff On Tue, Apr 24, 2001 at 01:47:17PM -0400, Andrew R. Reiter wrote: > > As in being able to say that for (and this might be a bad example) > kern.timecounter.* mibs, could all share a mutex which is really "bound" > to kern.timecounter in genera. Or do you mean just more generically the > idea that multiple sysctl's can share a mutex and who/what shares a mutex > is something to be decided? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message