From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 23 Nov 2009 14:11:12 +0100 (CET) Received: from gateway-1237.mvista.com ([206.112.117.35]:13184 "HELO imap.sh.mvista.com" rhost-flags-OK-OK-OK-FAIL) by ftp.linux-mips.org with SMTP id S1493091AbZKWNLE (ORCPT ); Mon, 23 Nov 2009 14:11:04 +0100 Received: from [192.168.11.189] (unknown [10.150.0.9]) by imap.sh.mvista.com (Postfix) with SMTP id 00C8C3ECC; Mon, 23 Nov 2009 05:10:52 -0800 (PST) Message-ID: <4B0A8A0B.60405@ru.mvista.com> Date: Mon, 23 Nov 2009 16:11:39 +0300 From: Sergei Shtylyov Organization: MontaVista Software Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.2) Gecko/20040803 X-Accept-Language: ru, en-us, en-gb MIME-Version: 1.0 To: Wu Zhangjin Cc: Ralf Baechle , Ingo Molnar , Thomas Gleixner , linux-mips@linux-mips.org, Michal Simek Subject: Re: [PATCH v5] MIPS: Add a high resolution sched_clock() via cnt32_to_63(). References: <39b95d02b37cd75d275b231c31abb00aefda9078.1258972025.git.wuzhangjin@gmail.com> In-Reply-To: <39b95d02b37cd75d275b231c31abb00aefda9078.1258972025.git.wuzhangjin@gmail.com> Content-Type: text/plain; charset=us-ascii; 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: 25060 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: sshtylyov@ru.mvista.com Precedence: bulk X-list: linux-mips Hello. Wu Zhangjin wrote: > From: Wu Zhangjin > (This v5 revision incorporates with the feedbacks from Ingo.) > This patch adds a cnt32_to_63() and MIPS c0 count based sched_clock(), > which provides high resolution. and also, one new kernel option > (HR_SCHED_CLOCK) is added to enable/disable this sched_clock(). > Without it, the Ftrace for MIPS will give useless timestamp information. > Because cnt32_to_63() needs to be called at least once per half period > to work properly, Differ from the old version, this v2 revision set up a > kernel timer to ensure the requirement of some MIPSs which have short c0 > count period. > Signed-off-by: Wu Zhangjin > diff --git a/arch/mips/kernel/csrc-r4k-hres.c b/arch/mips/kernel/csrc-r4k-hres.c > new file mode 100644 > index 0000000..2fe8be7 > --- /dev/null > +++ b/arch/mips/kernel/csrc-r4k-hres.c I don't think this is really good name for this file (one might think that this is another implementation of clocksource instead of some sched_clock() code tied to this particular clocksource), and I don't think we indeed needed to separate that thing into a file of its own, i.e. I'm against Ingo's suggestion in this case. WBR, Sergei