From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3CBD342C.4090309@bluewin.ch> Date: Wed, 17 Apr 2002 10:37:00 +0200 From: Wolfgang Grandegger MIME-Version: 1.0 To: srinivas pulipati Cc: Embedded Linux PPC List Subject: Re: rtlinux interrupt response References: <3CBD2584.B1504DA5@multitech.co.in> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: On 04/17/2002 09:34 AM, srinivas pulipati wrote: >hi all, > >i have downloaded denx rtlinux and ported it to my custom board for >study purpose. >my board is based on MPC860. rtlinux is working fine. > This is off topic here. Very likely you get better help from the rtlinux.org or rtai.org mailing lists. > > >i tried to measure the interrupt response time. >i am getting best case is 30microseconds and worst case is >150microsenconds. >couldn't understand why this much difference. >can anybody explain? or is there any thing wrong in my port? > With RTAI I measured sometime ago on a TQM860L, 50MHz, 8KB data cache: Min Max Average: No load : 13us 46us 14us while : ; do a=a ; done: 13us 46us 18us ping -f to target : 13us 46us 19us If I remember correctly, rtlinux has bigger overhead (more code). BTW: Denx has dropped support for rtlinux quite a while ago because of fsmlabs license policy (AFAIK, there is no open rtlinux for the MPC 8xx). Hope it helps, Wolfgang. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/