From owner-freebsd-arch Tue Oct 31 15:53:24 2000 Delivered-To: freebsd-arch@freebsd.org Received: from falla.videotron.net (falla.videotron.net [205.151.222.106]) by hub.freebsd.org (Postfix) with ESMTP id 95A4D37B4D7 for ; Tue, 31 Oct 2000 15:53:17 -0800 (PST) Received: from modemcable213.3-201-24.mtl.mc.videotron.ca ([24.201.3.213]) by falla.videotron.net (Sun Internet Mail Server sims.3.5.1999.12.14.10.29.p8) with ESMTP id <0G3B00743JOROY@falla.videotron.net> for freebsd-arch@FreeBSD.ORG; Tue, 31 Oct 2000 18:53:15 -0500 (EST) Date: Tue, 31 Oct 2000 18:57:50 -0500 (EST) From: Bosko Milekic Subject: Re: MP: per-CPU mbuf allocation lists In-reply-to: <200010312344.QAA18978@usr09.primenet.com> X-Sender: bmilekic@jehovah.technokratis.com To: Terry Lambert Cc: freebsd-arch@FreeBSD.ORG Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 31 Oct 2000, Terry Lambert wrote: > On the other hand, we know that significant concurrency can > be achieved, even with a single Big Giant Lock, by removing > resources from the conflict domain, rather than moving them > to private conflict domains. Per CPU resources simply do not > need locking or mutexes or atomic_t or similar protection: > they are inherently MP-safe. Is this 100% accurate? Don't we still need to protect even the per-CPU lists with a lock just in case we get an interrupt and get rescheduled because of a higher priority thread that wants execution? Is this possible? If it isn't the case, then ignore the question, but if it is, I agree that it still makes sense to have per-CPU resources available, just because it the lock contention is minimized. > > Terry Lambert > terry@lambert.org > --- > Any opinions in this posting are my own and not those of my present > or previous employers. Bosko Milekic bmilekic@technokratis.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message