> The effect of removing the two functions you noted (on 3.6 and earlier) > is to prevent RCU from checking for dyntick-idle CPUs, likely incurring > a cache miss for each CPU with interrupts disabled. If you have a lot > of CPUs (or even if NR_CPUS is large and you have a smaller number of > CPUs), this can result in user-space-visible delays. >
Paul, I built a kernel with NR_CPUS=48 and booted on a 48 cpu (logical) system. I do not see a difference in the test -- the variance is AFAICT just as large as if I had run with NR_CPUS=4096. P. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
