From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 10 Nov 2014 17:55:22 +0100 (CET) Received: from mail-ie0-f173.google.com ([209.85.223.173]:40523 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011908AbaKJQzUfopRV (ORCPT ); Mon, 10 Nov 2014 17:55:20 +0100 Received: by mail-ie0-f173.google.com with SMTP id tr6so9529988ieb.4 for ; Mon, 10 Nov 2014 08:55:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=NX3whFFWLmnxsMVrpGY3r+Nqibl9A42QP3oTxl+pZAI=; b=w486Znwb1FOLh85KoOwYEadCNG/5dpUggccGBihfTVS4irEvTvUBy3F0ZhmXr8GnNw 3CXWqlzLQLeY3YVzc2Nh6untGDMBrdhzi9sIDCTFsP9H7Snh/+1qMEUUYCBmLgJgAcfr pAkRv6tg9hD55majyIHttsaPDYvfuH9fiz7PxcIZNR5vO0N+d3mBjglE5SP2vuPIqM70 IN61mxfP2EWpPxF0v9Pm0cPwWaZ6gaW2nHXXW1cr12PA9kOJNgIRM6KcgCTOdlWLs+ZG A39WdfTH4Ack3+7eyufpHjvBiMg+FCxm3o5Ye6ynwXXZEDolRF0ylh1O4f9tA7TFb3zZ Y7QQ== X-Received: by 10.42.16.74 with SMTP id o10mr8725659ica.61.1415638511369; Mon, 10 Nov 2014 08:55:11 -0800 (PST) Received: from dl.caveonetworks.com (64.2.3.194.ptr.us.xo.net. [64.2.3.194]) by mx.google.com with ESMTPSA id oq6sm4988049igb.2.2014.11.10.08.55.10 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 10 Nov 2014 08:55:10 -0800 (PST) Message-ID: <5460EDED.3030600@gmail.com> Date: Mon, 10 Nov 2014 08:55:09 -0800 From: David Daney User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Joshua Kinard CC: Thomas Bogendoerfer , Ralf Baechle , Linux MIPS List Subject: Re: IP27: CONFIG_TRANSPARENT_HUGEPAGE triggers bus errors References: <54560D3B.8060602@gentoo.org> <5457CF0A.7020303@gmail.com> <5458272A.7050309@gentoo.org> <54582A91.8040401@gmail.com> <20141105160945.GB13785@linux-mips.org> <545C9D4D.4090501@gentoo.org> <545D0FC4.7020205@gmail.com> <545EB09C.40006@gentoo.org> <5460636A.5090401@gentoo.org> <20141110105106.GA4302@linux-mips.org> <20141110112039.GA7294@alpha.franken.de> <5460CA1D.9060907@gentoo.org> In-Reply-To: <5460CA1D.9060907@gentoo.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 43961 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ddaney.cavm@gmail.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 11/10/2014 06:22 AM, Joshua Kinard wrote: > On 11/10/2014 06:20, Thomas Bogendoerfer wrote: >> On Mon, Nov 10, 2014 at 11:51:06AM +0100, Ralf Baechle wrote: >>> Thomas, >>> >>> can you test CONFIG_TRANSPARENT_HUGEPAGE on an IP28? >>> >>> All in all the R10000's TLB is unproblematic; my gut feeling is that >>> rather something else specific to IP27 is spoiling the broth. >> >> I'll give it a spin later today. >> >> Thomas. > > Try testing with and without CONFIG_HUGETLBFS in the kernel. File systems -> > Pseudo filesystems -> HugeTLB file system support > > So far, it seems adding that option in with CONFIG_TRANSPARENT_HUGEPAGE makes > both IP27 and IP30 behave. Without, I get data bus errors or segfaults on IP27 > running Gentoo's "emerge" program on PAGE_SIZE_4K. > > IP30 seems to be fine on an R12000 with or without that option, but I only have > a dual R12K module to test against. I've only had the R14K dual module for a > few days, and I could not reproduce the bus errors on that module, either. So > I wonder if there is something funny with the hardware on the single R14K > module, which I did get IBE's on before. And whether that will behave once > CONFIG_HUGETLBFS is in the kernel. > > If so, maybe the fix is to make CONFIG_HUGETLBFS automatically selected if > CONFIG_TRANSPARENT_HUGEPAGE? > Yes, you may be on to something here. Certianly basic huge TLB support must be in place for TRANSPARENT_HUGEPAGE to work. It could be that the Kconfig symbols for the various portions of huge page support are missing the required dependencies. FWIW, I always build with a huge page Kconfig options set. I have: $ grep HUGE .config CONFIG_SYS_SUPPORTS_HUGETLBFS=y CONFIG_MIPS_HUGE_TLB_SUPPORT=y CONFIG_CPU_SUPPORTS_HUGEPAGES=y CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y # CONFIG_TRANSPARENT_HUGEPAGE_MADVISE is not set CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y CONFIG_HUGETLBFS=y CONFIG_HUGETLB_PAGE=y I suspect that you may not need CONFIG_HUGETLBFS, but CONFIG_HUGETLB_PAGE is probably essential. David Daney > --J >