From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Larmour To: Andrea Acquaviva Cc: "ecos-discuss@sources.redhat.com" Subject: Re: [ECOS]Strongarm rtc and oscr Date: Tue, 13 Feb 2001 09:05:00 -0000 Message-id: <3A896945.B4930864@redhat.com> References: <3A894DE3.A9D479FD@deis.unibo.it> X-SW-Source: 2001-02/msg00198.html Andrea Acquaviva wrote: > > I want to measure eCos multi-threading energy costs. I use it on the > assabet board. Have you looked at the tm_basic kernel test? > In order to measure context switch overhead, I need some infos about > timeslicing: > > - the option CYGNUM_KERNEL_SCHED_TIMESLICE_TICKS refers to 3.6864MHz > clock ticks? Yes. > - How does eCos use real time clock (RTC) and operating system timer > (OSCR) of > StrongARM 1110? An interesting question because we are considering changing the way it operates right now! The interesting part is in hal/arm/sa11x0/var/current/src/sa11x0_misc.c and hal_clock_rest() and hal_clock_read(). Currently it resets it to 0 each interrupt, but we may be about to change it to make it a freerunning counter. Jifl -- Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062 Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine