From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4BE27AA7.2070302@domain.hid> Date: Thu, 06 May 2010 10:15:35 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Xenomai-help] Problem getting the time with a kernel patched with xenomai List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Divi Oillo Cc: xenomai@xenomai.org Divi Oillo wrote: > Hi, I post this message because I need a little help. Hi, > (...) > gettimeofday(×tamp_sav,NULL); > nanosleep(&req,&req); > gettimeofday(×tamp,NULL); > (...) Note that your application does not benefit from any improvements made by Xenomai, it is using Linux services. > Why do I have +10010 =C2=B5s or +10011 =C2=B5s between each dating with= my xenomai > kernel and approximately +300 =C2=B5s with my non-patched kernel? > Thanks. To obtain such results, you are probably running your test on an idle system. But anyway, the problem is probably that the vanilla configuration probably has high resolutions timers running, whereas the Xenomai patched kernel has not. Whether high resolution timers are enabled is both a question of kernel-configuration (CONFIG_HIGHRES_TIMERS, CONFIG_X86_LOCAL_APIC, CONFIG_HPET have an influence), and a question of run-time decisions. You should find some hints in the kernel messages. Regards. --=20 Gilles.