Thanks for your note. The reason why I'm looking into process affinity is because I'm developing an acquisition system that needs 5microsecond (usec) latency response. RTLinux has a interrupt to task dispatch latency of 10-15 usec. I've discovered that by polling (busy waiting) the hardware, I can get responses of 2-3usec. The only problem is that I need a second data transport task. I'm thinking that if I put the polling/readout process on 1 cpu and the transport task on the other, I could guarantee (minus PCI contention) a sub-5 usec response.
On Tue, 5 Feb 2002, Chunky Kibbles wrote: > On Mon, Feb 04, 2002 at 11:24:47AM -0600, Ken Teh wrote: > > Does stock Linux 2.4 have a syscall to lock a process down to the > > specified cpu on a dual cpu M/B? Does RTlinux offer something similar? I > > vaguely remember it does but I cant seem to put my finger on what it might > > be called. > > Linux in and of itself doesn't have process affinity. Although it > shuold be noted that generally, linux is cleverer than you, and you > should leave it to schedule stuff on it's own. Linux /does/ try to > keep stuff on the same CPU, to take advantage of caches, and stuff, > but... > > The RTLinux kernel, though... > man 3 pthread_attr_getcpu_np > man 3 pthread_attr_setcpu_np > [note: even without your intervention, RTLinux threads pretty much > stick to the same CPU, anyways] > > Enjoy, > Gary (-; > -- [rtl] --- > To unsubscribe: > echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR > echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] > -- > For more information on Real-Time Linux see: > http://www.rtlinux.org/ > -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
