From owner-freebsd-hackers Tue Aug 7 0:16: 1 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from technokratis.com (modemcable052.174-202-24.mtl.mc.videotron.ca [24.202.174.52]) by hub.freebsd.org (Postfix) with ESMTP id D123D37B401 for ; Tue, 7 Aug 2001 00:15:57 -0700 (PDT) (envelope-from bmilekic@technokratis.com) Received: (from bmilekic@localhost) by technokratis.com (8.11.4/8.11.3) id f777IWS46144; Tue, 7 Aug 2001 03:18:32 -0400 (EDT) (envelope-from bmilekic) Date: Tue, 7 Aug 2001 03:18:32 -0400 From: Bosko Milekic To: Terry Lambert Cc: Matt Dillon , Zhihui Zhang , freebsd-hackers@FreeBSD.ORG Subject: Re: Allocate a page at interrupt time Message-ID: <20010807031832.A46112@technokratis.com> References: <200108051955.f75Jtk882156@earth.backplane.com> <3B6F8A6C.B95966B7@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3B6F8A6C.B95966B7@mindspring.com>; from tlambert2@mindspring.com on Mon, Aug 06, 2001 at 11:27:56PM -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, Aug 06, 2001 at 11:27:56PM -0700, Terry Lambert wrote: > I keep wondering about the sagicity of running interrupts in > threads... it still seems like an incredibly bad idea to me. > > I guess my major problem with this is that by running in > threads, it's made it nearly impossibly to avoid receiver > livelock situations, using any of the classical techniques > (e.g. Mogul's work, etc.). References to published works? > It also has the unfortunate property of locking us into virtual > wire mode, when in fact Microsoft demonstrated that wiring down > interrupts to particular CPUs was good practice, in terms of > assuring best performance. Specifically, running in virtual Can you point us at any concrete information that shows this? Specifically, without being Microsoft biased (as is most "data" published by Microsoft)? -- i.e. preferably third-party performance testing that attributes wiring down of interrupts to particular CPUs as _the_ performance advantage. > wire mode means that all your CPUs get hit with the interrupt, > whereas running with the interrupt bound to a particular CPU > reduces the overall overhead. Even what we have today, with Obviously. > the big giant lock and redirecting interrupts to "the CPU in > the kernel" is better than that... > > -- Terry -- Bosko Milekic bmilekic@technokratis.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message