From owner-freebsd-mips@FreeBSD.ORG Mon Jan 27 01:04:56 2014 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id A0FC25C4 for ; Mon, 27 Jan 2014 01:04:56 +0000 (UTC) Received: from mail.lhr1.as41113.net (mail.lhr1.as41113.net [91.208.177.22]) by mx1.freebsd.org (Postfix) with ESMTP id 655A11EA6 for ; Mon, 27 Jan 2014 01:04:55 +0000 (UTC) Received: from [10.193.246.16] (unknown [91.208.177.70]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.lhr1.as41113.net (Postfix) with ESMTPS id 3fCCRL36NQz7vXM for ; Mon, 27 Jan 2014 01:04:46 +0000 (UTC) Message-ID: <52E5B0AE.7030106@rewt.org.uk> Date: Mon, 27 Jan 2014 01:04:46 +0000 From: Joe Holden User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: freebsd-mips@freebsd.org Subject: Re: More trapframe panics References: <52E42A1B.3040907@rewt.org.uk> <52E524BD.7090106@rlwinm.de> <453F8F8F-41E5-4640-9683-5A8553AB0822@bsdimp.com> In-Reply-To: <453F8F8F-41E5-4640-9683-5A8553AB0822@bsdimp.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Jan 2014 01:04:56 -0000 On 26/01/2014 18:54, Warner Losh wrote: > > On Jan 26, 2014, at 9:04 AM, Juli Mallett wrote: > >> On Sun, Jan 26, 2014 at 7:07 AM, Jan Bramkamp wrote: >>> >>> Would increasing KSTACK_PAGES from two to three or four help? What are >>> the trade-offs involved in choosing KSTACK_PAGES for something like the >>> EdgeMax Lite? >> >> >> That's exactly what needs to happen in all 64-bit MIPS kernels. Unlike >> some other architectures, KSTACK_PAGES cannot simply be increased, >> however. All of the code which handles loading the kernel stack and >> keeping it mapped, etc., assumes that it takes up exactly one TLB entry, >> i.e. 2 pages. One could simply double KSTACK_PAGES for 64-bit builds and >> modify the code to support the case of 2 or 4 pages, which would keep the >> code as gross as it is today and not buy much flexibility, but might be >> worthwhile as a short-term fix. Being able to support arbitrary values of >> KSTACK_PAGES (or at least arbitrary multiples of 2 up to the maximum number >> of wired TLB entries times 2) would be better. > > I hacked together a kludge that quadrupled this by going to the next larger page size for stack pages in the TLB, but hit something ugly when I did that... But I've lost that code, so maybe I should try again to see if I'm more clever the second time. > > This is one of the things that makes it hard to have a nice native build server on mips64... > > Warner > I have plenty of hardware (pretty much just spare ERLs) that you can use if you want - unless you can give me some ideas on other mips64 hardware that would be useful in which case I can make that available too.