From owner-freebsd-arch@freebsd.org Tue Oct 20 20:36:33 2015 Return-Path: Delivered-To: freebsd-arch@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C05D4A0A7DF for ; Tue, 20 Oct 2015 20:36:33 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A08CFF47 for ; Tue, 20 Oct 2015 20:36:33 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from ralph.baldwin.cx (c-73-231-226-104.hsd1.ca.comcast.net [73.231.226.104]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id D6D8EB94F for ; Tue, 20 Oct 2015 16:36:31 -0400 (EDT) From: John Baldwin To: 'freebsd-arch' Subject: Retiring in-tree GDB Date: Tue, 20 Oct 2015 13:36:28 -0700 Message-ID: <2678091.es0AGJQ0Ou@ralph.baldwin.cx> User-Agent: KMail/4.14.3 (FreeBSD/10.2-PRERELEASE; KDE/4.14.3; amd64; ; ) MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Tue, 20 Oct 2015 16:36:31 -0400 (EDT) X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Oct 2015 20:36:33 -0000 When this topic was last raised (by Warner I believe), the primary objection (certainly my main one) was that the in-tree kgdb was the only kernel debugger available. kgdb is now available via the devel/gdb port in ports (and as of last week was enabled by default, so 'pkg install gdb' will get you a kgdb binary). The kgdb in ports is in general superior to the one in the base system. It is a cross debugger by default (and with my pending patches to libkvm it even supports cross debugging of vmcores). There are some issues still with devel/gdb: namely it does not currently support some of the platforms supported by our in tree gdb such as arm and mips. For these platforms I think the in-tree gdb will need to remain until there is a suitable alternative. However, I would like to propose that we retire the in-tree GDB for some of our platforms (namely x86) for 11. In particular, I think we should default to enabling lldb and disabling gdb for platforms that meet the following criteria: 1) devel/gdb works including thread and kgdb support 2) lldb works We could perhaps be more aggressive and handle lldb and gdb toggles independently, but I think we want to ship some sort of userland debugger out of the box on all of our platforms. The question I think might be if we end up with platforms where 1) is true but 2) is not (such as powerpc). I believe that these conditions are only true for x86 currently. Comments? -- John Baldwin