From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17353 invoked by alias); 1 Oct 2007 08:41:58 -0000 Received: (qmail 17344 invoked by uid 22791); 1 Oct 2007 08:41:57 -0000 X-Spam-Status: No, hits=-2.1 required=5.0 tests=AWL,BAYES_00,DK_POLICY_SIGNSOME,FORGED_RCVD_HELO X-Spam-Check-By: sourceware.org Received: from wildebeest.demon.nl (HELO gnu.wildebeest.org) (83.160.170.119) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 01 Oct 2007 08:41:55 +0000 Received: from dijkstra.wildebeest.org ([192.168.1.29]) by gnu.wildebeest.org with esmtp (Exim 4.63) (envelope-from ) id 1IcGqe-0004zp-Hj; Mon, 01 Oct 2007 10:41:53 +0200 Subject: Re: Optimizing watchpoints From: Mark Wielaard To: Roland McGrath Cc: Phil Muldoon , Frysk Hackers In-Reply-To: <20071001012529.D264A4D0325@magilla.localdomain> References: <46FD7036.2010500@redhat.com> <20071001012529.D264A4D0325@magilla.localdomain> Content-Type: text/plain Date: Mon, 01 Oct 2007 08:41:00 -0000 Message-Id: <1191228112.3842.24.camel@dijkstra.wildebeest.org> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-2.fc6) Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-IsSubscribed: yes Mailing-List: contact frysk-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: frysk-owner@sourceware.org X-SW-Source: 2007-q4/txt/msg00001.txt.bz2 Hi Roland, On Sun, 2007-09-30 at 18:25 -0700, Roland McGrath wrote: > (For compatibility, ptrace > itself will use that facility to virtualize the demands made by > PTRACE_SET_DEBUGREG and the like. ptrace uses a known priority number that > is fairly high, so that some system-wide or other background tracing would > have to knowingly intend to interfere with traditional user application use > by choosing an even higher priority.) Just a FYI. I see (through a quick kernel grep) PTRACE_SET_DEBUGREG is only available on powerpc. For x86[_64] frysk pokes at the hardware debug registers through the USR area and getting/setting them "directly". This might have to become a special case of the above. Cheers, Mark