From owner-freebsd-smp Sat Jun 12 14:22:43 1999 Delivered-To: freebsd-smp@freebsd.org Received: from mail.rdc1.sfba.home.com (ha1.rdc1.sfba.home.com [24.0.0.66]) by hub.freebsd.org (Postfix) with ESMTP id 96DFC14DB2 for ; Sat, 12 Jun 1999 14:22:42 -0700 (PDT) (envelope-from adsharma@c62443-a.frmt1.sfba.home.com) Received: from c62443-a.frmt1.sfba.home.com ([24.0.69.165]) by mail.rdc1.sfba.home.com (InterMail v4.01.01.00 201-229-111) with ESMTP id <19990612212242.RTPG8807.mail.rdc1.sfba.home.com@c62443-a.frmt1.sfba.home.com>; Sat, 12 Jun 1999 14:22:42 -0700 Received: (from adsharma@localhost) by c62443-a.frmt1.sfba.home.com (8.8.7/8.8.7) id OAA26293; Sat, 12 Jun 1999 14:22:42 -0700 To: Alfred Perlstein Cc: smp@FreeBSD.ORG Subject: Re: simple_lock() ? References: From: Arun Sharma Mime-Version: 1.0 (generated by tm-edit 7.106) Content-Type: text/plain; charset=US-ASCII Date: 12 Jun 1999 14:22:42 -0700 In-Reply-To: Alfred Perlstein's message of "Sat, 12 Jun 1999 15:09:16 -0500 (EST)" Message-ID: Lines: 22 X-Mailer: Gnus v5.5/Emacs 20.3 Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Alfred Perlstein writes: > On 12 Jun 1999, Arun Sharma wrote: > > > Alfred Perlstein writes: > > > > > The simple_lock/unlock/try_lock stuff looks like precursor work towards > > > finer grained SMP. Is this true? right now it looks like it amounts > > > to a NOP in SMP and UP systems, is this also true? > > > > It is a nop in UP systems, but calls some locking primitive on a SMP > > system. > > because of the BGL i don't see why his is nessesary... > > confused, Here's a guess: the comments in simplelock.s indicate that the locking code came from 4.4BSD lite2. But you're right - in a giant locked kernel, they are wasteful. -Arun To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message