From owner-freebsd-smp Sun Jun 25 10:43: 7 2000 Delivered-To: freebsd-smp@freebsd.org Received: from mail.interware.hu (mail.interware.hu [195.70.32.130]) by hub.freebsd.org (Postfix) with ESMTP id 8991437B737 for ; Sun, 25 Jun 2000 10:42:44 -0700 (PDT) (envelope-from julian@elischer.org) Received: from dakar-05.budapest.interware.hu ([195.70.51.69] helo=jules.elischer.org) by mail.interware.hu with smtp (Exim 3.12 #1 (Debian)) id 136GfV-0006XD-00; Sun, 25 Jun 2000 19:58:06 +0200 Message-ID: <39564465.794BDF32@elischer.org> Date: Sun, 25 Jun 2000 10:41:57 -0700 From: Julian Elischer X-Mailer: Mozilla 3.04Gold (X11; I; FreeBSD 5.0-CURRENT i386) MIME-Version: 1.0 To: Jason Evans Cc: smp@freebsd.org Subject: Re: SMP meeting summary References: <20000624235605.D8965@blitz.canonware.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Jason Evans wrote: > - Netgraph poses locking performance problems, since locks have to be > released at multiple potential transfer points, regardless of whether > Netgraph is in use. This problem also exists with System V STREAMS. > During the meeting we didn't come to a clear consensus on how much of > a problem this really is. > I think this is a mis-stated issue. There is no REQUIREMENT that locks be released or held at every transfer between modules. While it is the case that some modules may require locking operations, it cannot be said that there is a 1:1 correspondence between locks and modules. A packet could wuite easily travel thought quite a number of modules without any additional locking work. Many modules would have no resources worth protecting.. (at least in the common case) -- __--_|\ Julian Elischer / \ julian@elischer.org ( OZ ) World tour 2000 )_.---._/ presently in: Budapest v To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message