From owner-freebsd-mips@FreeBSD.ORG Sun Jan 26 18:54:14 2014 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id DC166DB3 for ; Sun, 26 Jan 2014 18:54:14 +0000 (UTC) Received: from mail-ig0-f172.google.com (mail-ig0-f172.google.com [209.85.213.172]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 9DAD61102 for ; Sun, 26 Jan 2014 18:54:14 +0000 (UTC) Received: by mail-ig0-f172.google.com with SMTP id k19so7103961igc.5 for ; Sun, 26 Jan 2014 10:54:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:subject:mime-version:content-type:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=KLV/w5oNLM2/jUvQHYaqa+QumNnBH/fZKwKErF26iXU=; b=YWaWjSWSFHAeJgE9ss2KTH5cbASPUYub9Ek+K/0l1uYHLjKEfMiEm4hV+GUXvFZB9V GeWUT1PSCvlc8oI1L8MAaK9HeRK3sN1d14YizqcYoyjc+9QdjGOlI4Y8Ja0ApwagBOLM BbZdB0K/Bsqof0N47JB7KzfhKaFk7qIvWNcRW3CLYvEgb1Xa1MtdK/Iil2GaQv3J7wnT PJjv6fQBJaS5GmLaljYYBgQ3s5HLomy9bUZIrrfVXg+qAiujfjCs6gEmeMRydtfxjavW rQTtV2wJ8raccLxqxmf/flwd7+U89RKI57jnolyjT/xm32YZ+YhO8jnoiekWpoa8JGIt 5CEQ== X-Gm-Message-State: ALoCoQnYsSv6LMTOi3NW1+fExz+RdrPGlvqRxLKLKHZM+RMJqONgjdZyWYan7uTJz0hh+2iA0czG X-Received: by 10.51.15.130 with SMTP id fo2mr14111284igd.28.1390762447484; Sun, 26 Jan 2014 10:54:07 -0800 (PST) Received: from fusion-mac.bsdimp.com (50-78-194-198-static.hfc.comcastbusiness.net. [50.78.194.198]) by mx.google.com with ESMTPSA id ac3sm35554067igd.4.2014.01.26.10.54.06 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 26 Jan 2014 10:54:06 -0800 (PST) Sender: Warner Losh Subject: Re: More trapframe panics Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: text/plain; charset=us-ascii From: Warner Losh In-Reply-To: Date: Sun, 26 Jan 2014 11:54:05 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <453F8F8F-41E5-4640-9683-5A8553AB0822@bsdimp.com> References: <52E42A1B.3040907@rewt.org.uk> <52E524BD.7090106@rlwinm.de> To: Juli Mallett X-Mailer: Apple Mail (2.1085) 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 18:54:14 -0000 On Jan 26, 2014, at 9:04 AM, Juli Mallett wrote: > On Sun, Jan 26, 2014 at 7:07 AM, Jan Bramkamp wrote: >>=20 >> 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? >=20 >=20 > 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