From owner-freebsd-java@FreeBSD.ORG Sat Feb 22 17:02:42 2014 Return-Path: Delivered-To: freebsd-java@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 98E30604; Sat, 22 Feb 2014 17:02:42 +0000 (UTC) Received: from mail-la0-x232.google.com (mail-la0-x232.google.com [IPv6:2a00:1450:4010:c03::232]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 2F8941884; Sat, 22 Feb 2014 17:02:41 +0000 (UTC) Received: by mail-la0-f50.google.com with SMTP id ec20so3573461lab.23 for ; Sat, 22 Feb 2014 09:02:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=LA4nul6Ut17/JKDS3S+uBcNv9ei9PiVS9gId/JbGsEw=; b=FpfsAMUKYtbJxDwF8xF386IUPrXod0nIqhqG/VnrE9B7M+P4m8w2VrPaZmtYUKIH89 sZmBZmja2aRPke23DLLNXQe21tpqKAkRvL3azb10/3Ay6yrga7qQmgWG2ufychMY+E5z 3QBzX4Cc9ZvRc0OlUXlG+grHVdwrJz3RfgMy3SMbL5j69/PGowC3D29Gl+i4ng/Yvj+B icefwYu5ix5IS4i74znJZBEe8xLu5vByNKt3DWHZdrqWwm+dEG/Aym+AEO9rcFOtKbAY BMs2t9tiRMr+PRjn68g2IZWrGEUyiJs2hb4TcZWGe17ZGNczibxLP4yJhHfUMwyAYCZ3 tYHQ== MIME-Version: 1.0 X-Received: by 10.112.40.114 with SMTP id w18mr6987318lbk.20.1393088559136; Sat, 22 Feb 2014 09:02:39 -0800 (PST) Sender: crodr001@gmail.com Received: by 10.112.30.211 with HTTP; Sat, 22 Feb 2014 09:02:39 -0800 (PST) In-Reply-To: <5307DD8F.5020501@FreeBSD.org> References: <5307DD8F.5020501@FreeBSD.org> Date: Sat, 22 Feb 2014 09:02:39 -0800 X-Google-Sender-Auth: j6FtK1U9l8bHKELvz5fnIqu1kNc Message-ID: Subject: Re: vm.pmap.pcid_enabled="0" seems to eliminate Java/Jenkins crashing problems in FBSD 10 From: Craig Rodrigues To: Jung-uk Kim Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: FreeBSD Release Engineering Team , attilio@freebsd.org, Xin Li , FreeBSD Security Team , Dmitry Sivachenko , "freebsd-java@freebsd.org" X-BeenThere: freebsd-java@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Porting Java to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Feb 2014 17:02:42 -0000 On Fri, Feb 21, 2014 at 3:13 PM, Jung-uk Kim wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 2014-02-21 17:54:58 -0500, Attilio Rao wrote: > > > No, it is enabled by default on all 10+ AFAICT. > > > http://svnweb.freebsd.org/base/head/sys/amd64/amd64/pmap.c?annotate=261781#l370 > > http://svnweb.freebsd.org/base/stable/10/sys/amd64/amd64/pmap.c?annotate=260467#l370 > > http://svnweb.freebsd.org/base/releng/10.0/sys/amd64/amd64/pmap.c?annotate=259065#l370 > Yes, I looked at the code with Xin Li, and Xin showed me that the default behavior of the code is to examine the capabilities of the CPU, and if the PCID feature is available, it then sets vm.pmap.pcid_enabled=1. So my next question is: where is the bug? If it: -> bug in code implementatino of pcid? -> bug in FreeBSD VM? -> bug in microcode of CPU? For now I can work around this by turning the feature off, but it would be nice to fix this, since a lot of effort has been done to improve performance. -- Craig