From owner-freebsd-mips@FreeBSD.ORG Sun Jan 26 16:05:17 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 AE33FD71 for ; Sun, 26 Jan 2014 16:05:17 +0000 (UTC) Received: from mail-la0-f45.google.com (mail-la0-f45.google.com [209.85.215.45]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 340E11232 for ; Sun, 26 Jan 2014 16:05:16 +0000 (UTC) Received: by mail-la0-f45.google.com with SMTP id b8so3775894lan.4 for ; Sun, 26 Jan 2014 08:05:08 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc:content-type; bh=478u6RjFicKdVuPuYBpK+ymHLEQan4td7gyBSAsxiO0=; b=Tb/CvWa04Fs0v2znCfyAMi70vocpNbQ6HcA+EbJGZ19lzX5sLb2/QyO35ked04I7NB 0z1SsABMoTyCe4miXBtwf5maZyh92sINaBspbhKxJEDLtzHeZ9Ysvz2T7TBDscxzIRaO jkcpKZKTl+aGE93wFukYQztaeExpEtcSahbI4Ox9z4Z5EsU2ZzJCkT3jEeAnoyec/yrD IIfpWpXWVvEDRVoa/blqQXxjuBmUWnUc1ArzclC2Tt8hv3iN3NfjMtUZQQrDZ/fYftY5 mdo6B8r+TNNy7klLbvqUyOF2xhnrEpl2qUU/HUsb4B/3jcDr4LjyEdHr5l7luGlVsrU6 9Zbg== X-Gm-Message-State: ALoCoQkKoaXBwJHEty5FfJF7PTpAHuwzhoM0XSpoUZRnpGsPBVkZLGpEl4wORZokA0vtZigbDIHK X-Received: by 10.152.161.234 with SMTP id xv10mr17874lab.41.1390752308806; Sun, 26 Jan 2014 08:05:08 -0800 (PST) MIME-Version: 1.0 Sender: juli@clockworksquid.com Received: by 10.152.129.170 with HTTP; Sun, 26 Jan 2014 08:04:48 -0800 (PST) In-Reply-To: <52E524BD.7090106@rlwinm.de> References: <52E42A1B.3040907@rewt.org.uk> <52E524BD.7090106@rlwinm.de> From: Juli Mallett Date: Sun, 26 Jan 2014 08:04:48 -0800 X-Google-Sender-Auth: YbK7H_380gXKFN1TfNTVP3FBBV0 Message-ID: Subject: Re: More trapframe panics To: Jan Bramkamp Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: "freebsd-mips@FreeBSD.org" 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: Sun, 26 Jan 2014 16:05:17 -0000 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. Thanks, Juli.