From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 12 May 2002 22:49:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 12 May 2002 22:49:34 -0400 Received: from web20110.mail.yahoo.com ([216.136.226.47]:8459 "HELO web20110.mail.yahoo.com") by vger.kernel.org with SMTP id ; Sun, 12 May 2002 22:49:33 -0400 Message-ID: <20020513024933.74553.qmail@web20110.mail.yahoo.com> Date: Sun, 12 May 2002 19:49:33 -0700 (PDT) From: Jennifer Huang Subject: Re: Question about cpu time accuracy. To: Kurt Wall Cc: linux-kernel@vger.kernel.org In-Reply-To: <20020512185709.C623@marta> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Thanks very much for your information. Just one more question, does it work for 2.4.18? Thanks. --- Kurt Wall wrote: > Scribbling feverishly on May 12, Jennifer Huang > managed to emit: > > Hi all, > > > > I have a question about cpu time accuracy. > > > > I am using kernel 2.4.18. But, when I tried > "utime" > > and "nanosleep" to get a process suspended, it > only > > worked in 10ms granularity, and it's no way to > sleep > > for 1 microsecond. > > The standard kernel timer has a resolution of 1/HZ, > which is 10ms on > an x86. You could try a scheduling policy of > SCHED_FIFO or SCHED_RR, > but this only gets you 2ms resolution. > > > Anyone can help me out of this? > > There are patches available for high resolution > timers: > > http://sourceforge.net/projects/high-res-timers/ > http://www.cs.wisc.edu/paradyn/libhrtime/ > > Kurt > -- > Anarchy may not be the best form of government, but > it's better than no > government at all. > - > 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/ __________________________________________________ Do You Yahoo!? LAUNCH - Your Yahoo! Music Experience http://launch.yahoo.com