From owner-freebsd-arch Tue Oct 16 10:34:28 2001 Delivered-To: freebsd-arch@freebsd.org Received: from femail27.sdc1.sfba.home.com (femail27.sdc1.sfba.home.com [24.254.60.17]) by hub.freebsd.org (Postfix) with ESMTP id 517F937B409 for ; Tue, 16 Oct 2001 10:34:19 -0700 (PDT) Received: from laptop.baldwin.cx ([24.2.39.156]) by femail27.sdc1.sfba.home.com (InterMail vM.4.01.03.20 201-229-121-120-20010223) with ESMTP id <20011016173418.YGNO12089.femail27.sdc1.sfba.home.com@laptop.baldwin.cx>; Tue, 16 Oct 2001 10:34:18 -0700 Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <20011016100520.E63982@iguana.aciri.org> Date: Tue, 16 Oct 2001 10:34:18 -0700 (PDT) From: John Baldwin To: Luigi Rizzo Subject: Re: where to put support for timestamping kernel events ? Cc: arch@FreeBSD.org Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 16-Oct-01 Luigi Rizzo wrote: > On Tue, Oct 16, 2001 at 09:27:07AM -0700, John Baldwin wrote: >> >> On 15-Oct-01 Luigi Rizzo wrote: >> > [Apparently this kind of question is better asked on -arch, >> > so sorry for the repost, here it goes again... and in the meantime >> > i have had some time to elaborate on names and locations.] >> >> Note that KTR has somewhat similar support for this, though it currently > > what is KTR ? any pointers ? (sorry but i am not familiar > with -current, where this seems to be...) KTR is an kernel event trace mechanism. current includes both ktr(4) and ktr(9) manpages. It basically allows you to log events in a printf-style fashion in the kernel including a timestamp among other things. >> doesn't use the TSC. It could be changed to use cpu_cyclecount() (which is >> a >> MI interface which uses the TSC when it can) perhaps which might help. >> Unfortunately, the KTR buffr isn't exported via sysctl(8) at the moment. > > well, the sysctl export is really trivial to do. Except on an SMP system when aother CPU may be sticking items in the buffer while you are exporting it. > cheers > luigi -- John Baldwin -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message