On Fri, Sep 16, 2011 at 5:08 AM, Kernel Piddu <kernelpiddu@gmail.com> wrote:
I have a multi processor system/machine and I would like dedicate a CPU entirely to listen on to a port. I would greatly appreciate if you could tell me how this can be done.
Thanks!
doing this in the kernel, is perhaps not really recommended, and linux kernel is become UNIX-non-compliant if such features were ever provided. but userspace, is definitely possible, but is always a suggestive tuning....the kernel can always override your request: http://www.cyberciti.biz/tips/setting-processor-affinity-certain-task-or-pro... but this is per-process, if u want per-port IRQ handling attach to the core, then this is going to affect the algorithm kernel used for SoftIRQ handling: doing a "cat /proc/softirqs" on my system: CPU0 CPU1 CPU2 CPU3 HI: 0 0 0 0 TIMER: 563854 591025 0 0 NET_TX: 7 6 0 0 NET_RX: 17486 19250 0 0 BLOCK: 28888 3784 0 0 BLOCK_IOPOLL: 0 0 0 0 TASKLET: 399230 391008 0 0 SCHED: 116858 119604 0 0 HRTIMER: 978 610 0 0 RCU: 158513 192567 0 0 i can see that the IRQ processing is skewed, but then unless i have an overall picture of what every core is doing.....not advisable to touch that. anyway looking at the "processes": root 3 2 0 16:59 ? 00:00:00 [ksoftirqd/0] root 7 2 0 16:59 ? 00:00:00 [ksoftirqd/1] only two tasklet thread are spawned to handle the these softirq at each core. i suspect some error in the interpreting the number of cores here, as there is only two core. (/proc/cpuinfo). good reading on these internals: http://lwn.net/Articles/308117/ http://www.wil.cx/matthew/lca2003/paper.pdf -- Regards, Peter Teoh