From owner-freebsd-arch Tue Aug 20 8:35:17 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EE3BB37B400 for ; Tue, 20 Aug 2002 08:35:15 -0700 (PDT) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.FreeBSD.org (Postfix) with ESMTP id AE64B43E3B for ; Tue, 20 Aug 2002 08:35:15 -0700 (PDT) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id 822BFAE165; Tue, 20 Aug 2002 08:35:15 -0700 (PDT) Date: Tue, 20 Aug 2002 08:35:15 -0700 From: Alfred Perlstein To: Andrew Gallatin Cc: Bruce Evans , Ian Dowse , arch@FreeBSD.ORG Subject: Re: Solving the stack gap issue Message-ID: <20020820153515.GL75574@elvis.mu.org> References: <200208171918.aa72556@salmon.maths.tcd.ie> <20020818055951.N12475-100000@gamplex.bde.org> <15714.17605.575558.398279@grasshopper.cs.duke.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15714.17605.575558.398279@grasshopper.cs.duke.edu> User-Agent: Mutt/1.3.27i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Andrew Gallatin [020820 06:32] wrote: > > For example, why do we check MPSAFE and conditionally grab and release > GIANT in syscall instead of just grabbing/releasing it in the syscall > itself? A few thousand instructions worth of bloat might be worth 2 > compares in the critical path.. Also, if the copyin fails, why do we > not just set the ret value and jump past the call, rather than setting > error and doing an extra compare a few lines later? Grunt work that just needs to be done. I can take a shot at it if no one else is currently. -- -Alfred Perlstein [alfred@freebsd.org] [#bsdcode/efnet/irc.prison.net] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message