From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id g0LNL5a17707 for linux-mips-outgoing; Mon, 21 Jan 2002 15:21:05 -0800 Received: from dea.linux-mips.net (localhost [127.0.0.1]) by oss.sgi.com (8.11.2/8.11.3) with ESMTP id g0LNL2P17683 for ; Mon, 21 Jan 2002 15:21:02 -0800 Received: (from ralf@localhost) by dea.linux-mips.net (8.11.1/8.11.1) id g0K0OF317384; Sat, 19 Jan 2002 16:24:15 -0800 Date: Sat, 19 Jan 2002 16:24:15 -0800 From: Ralf Baechle To: "Kevin D. Kissell" Cc: "H . J . Lu" , Ulrich Drepper , GNU libc hacker , linux-mips@oss.sgi.com Subject: Re: thread-ready ABIs Message-ID: <20020119162415.B31028@dea.linux-mips.net> References: <20020118101908.C23887@lucon.org> <01b801c1a081$3f6518e0$0deca8c0@Ulysses> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <01b801c1a081$3f6518e0$0deca8c0@Ulysses>; from kevink@mips.com on Sat, Jan 19, 2002 at 01:35:38AM +0100 X-Accept-Language: de,en,fr Sender: owner-linux-mips@oss.sgi.com Precedence: bulk On Sat, Jan 19, 2002 at 01:35:38AM +0100, Kevin D. Kissell wrote: > Thank you for posting this to linux-mips, since I'm not sure > that anyone at MIPS is on the GNU_libc_hacker list. > > It would, in principle, be possible to save/restore k0 > or k1 (but not both) if no other clever solution can be found. > There are other VM OSes that manage to do so for MIPS, > for other outside-the-old-ABI reasons. It does, of course, > add some instructions and some memory traffic to the > low-level exception handling , and we would have to look > at whether we would want to make such a feature standard > or specific to a "thread-ready" kernel build. Changing the kernel for the small number of threaded applications that exists and taking a performance impact for the kernel itself and anything that's using threads is an exquisite example for a bad tradeoff. Ralf