From owner-freebsd-arch Tue Nov 28 15:27:24 2000 Delivered-To: freebsd-arch@freebsd.org Received: from pike.osd.bsdi.com (pike.osd.bsdi.com [204.216.28.222]) by hub.freebsd.org (Postfix) with ESMTP id 5B92537B401 for ; Tue, 28 Nov 2000 15:27:22 -0800 (PST) Received: from laptop.baldwin.cx (john@dhcp246.osd.bsdi.com [204.216.28.246]) by pike.osd.bsdi.com (8.11.1/8.9.3) with ESMTP id eASNQkC95291; Tue, 28 Nov 2000 15:26:46 -0800 (PST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <3A242FAF.313295F0@elischer.org> Date: Tue, 28 Nov 2000 15:26:59 -0800 (PST) From: John Baldwin To: Julian Elischer Subject: Re: Thread-specific data and KSEs Cc: arch@FreeBSD.org, Daniel Eischen Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 28-Nov-00 Julian Elischer wrote: > Daniel Eischen wrote: >> >> On Mon, 27 Nov 2000, Julian Elischer wrote: >> > >> > One thing I just realised: >> > >> > If we are using defered FP state saving and restoring in the kernel, then >> > we >> > will have troubles with that when switching threads in userland, since the >> > handler for that is in the kernel. Of course we could set the place for it >> > in >> > the KSE mailbox and let the kernel save the information when it needs it. >> >> Our current threads library knows when to save and restore FP state; >> it currently only happens when a signal is received (for i386, I think >> alpha FP state is always saved both in jmp_buf and ucontext_t) > > That's comforting. > > I was looking at the ia64 specs.. > that thing presents some interesting challenges in regards to > the 'intelligent' stack it has. It will be very hard to play > games with it's stack when it's cached inside the chip. I > presume they have a scheme to allow such things as threads, > but it looks a mess from here. You can disable the RSE and flush it out. This is done during context switches for example, and to setup the stack frame for signal handling I believe, though signal handling isn't quite finished yet. -- John Baldwin -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message