From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?H=E5kon?= Hallingstad Subject: Re: Nanoseconds precision Date: Thu, 25 Aug 2005 15:41:39 +0200 Message-ID: <20050825134139.GA31343@hydrogen.ion.no> References: <6a00c8d505082505406cec57eb@mail.gmail.com> <6a00c8d505082506372bc67a42@mail.gmail.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <6a00c8d505082506372bc67a42@mail.gmail.com> Sender: linux-c-programming-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linux C Programming Or you may use the "rdtsc" (Read Time Stamp Counter) assembly instruction. On Thu, Aug 25, 2005 at 03:37:27PM +0200, Steve Graegert wrote: > On 8/25/05, Ronaldo.Afonso@cyclades.com wrote: > > > > All the functions in the libc do not show me nanosecond's precision. What > > they do is get a microsecond number and multiply it by 1000. So, I realized > > that it has to be that way because it's impossible to get a nanosecond's > > precison on a machine with a 2Ghz clock. The system needs more than a > > nanosecond to execute an instruction, so any nanosecond's precision, at > > leas on a 2Ghz machine, should be inaccurate. I'm just sharing what I've > > found. > > > > Anyway, I'd like to thank everyone who helped me with this question. > > #include > int clock_gettime(clockid_t clock_id, struct timespec *tp); > > timespec.nv_nsec provides nanosecond resolution. Use CLOCK_REALTIME > for clock_id. > > Regards > > \Steve > > -- > > Steve Graegert > Software Consultancy {C/C++ && Java && .NET} > Mobile: +49 (176) 21248869 > Office: +49 (9131) 7126409 > - > To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html