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]thread switch frequency Date: Fri, 20 Apr 2001 02:23:00 -0000 Message-id: <3AE00009.2BC3F600@redhat.com> References: <3ADFFA65.CC964CFF@deis.unibo.it> X-SW-Source: 2001-04/msg00252.html Andrea Acquaviva wrote: > > Hi, > I have a question about eCos mlqueue scheduler. > If there are two threads (making a matrix multiplication), running with > the same priority, they switch with a frequency given by: > > f_clock/CYGNUM_KERNEL_SCHED_TIMESLICE_TICKS, > > where f_clock in the case of strongarm1110 (assabet) is 3.6864MHz. > > Is this correct or is there something else that affects the switching > frequency? The timer that drives the kernel clock interrupt is at 3.6864MHz yes, but it is has been programmed to only actually interrupt when its counter reaches 36864, which corresponds to every 10ms. And only 1 in CYGNUM_KERNEL_SCHED_TIMESLICE_TICKS of those causes a timeslice. 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