Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759783AbXHEXk0 (ORCPT ); Sun, 5 Aug 2007 19:40:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756641AbXHEXkO (ORCPT ); Sun, 5 Aug 2007 19:40:14 -0400 Received: from wa-out-1112.google.com ([209.85.146.176]:12072 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755792AbXHEXkM (ORCPT ); Sun, 5 Aug 2007 19:40:12 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=sf8ioRf9BMrfVUzHAJ8WIYcPY0yEOH4Tmzv5sMenJDVyhSrv0cAuOrilx8T5W+QMqE/lLOHBJOSfOjDzTQeXMNxDBwkmWQfwCUVUbtPGWQalDewKFfhhTqse2hubu4r5KsqkjgsvDbJRVqnhyPKuy7yaoJ9J9lXeQ+8FIkeCVcI= Message-ID: Date: Sun, 5 Aug 2007 19:40:11 -0400 From: "Michael Chang" To: "H. Peter Anvin" Subject: Re: rtc max frequency setting Cc: "Jan Engelhardt" , "Linux Kernel Mailing List" , rtc-linux@googlegroups.com In-Reply-To: <46B5148E.50302@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <46B5148E.50302@zytor.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1898 Lines: 47 On 8/4/07, H. Peter Anvin wrote: > Jan Engelhardt wrote: > > Hi, > > > > with the old rtc.ko module, there was a /proc/sys/dev/rtc/max-user-freq > > that could be set. With rtc_cmos.ko (or the new rtc infrastructure in > > general), I am missing this file. Where can I set the max-user-freq now, > > or is this obsolete now? (mplayer prefers to have user-freq to be >= 1024.) > > > > Qemu wants something like this too. Both of these really want something > else, which is a high-frequency userspace timer. For mplayer, you can use -softsleep, but that uses a lot of CPU, and you're probably already using a great deal of CPU for video decoding, so it might be less than optimal. -softsleep Time frames by repeatedly checking the current time instead of asking the kernel to wake up MPlayer at the correct time. Useful if your kernel timing is imprecise and you cannot use the RTC either. Comes at the price of higher CPU consumption. And apparently, the build of MPlayer[1] that I have doesn't need rtc, except on slower machines, according to the man page: -rtc (RTC only) Turns on usage of the Linux RTC (realtime clock - /dev/rtc) as timing mechanism. This wakes up the process every 1/1024 seconds to check the current time. Useless with modern Linux kernels configured for desktop use as they already wake up the process with similar accuracy when using normal timed sleep. [1] MPlayer dev-SVN-r23777-4.1.2 (C) 2000-2007 MPlayer Team -- Michael Chang Please avoid sending me Word or PowerPoint attachments. Send me ODT, RTF, or HTML instead. See http://www.gnu.org/philosophy/no-word-attachments.html Thank you. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/