On Thu, 23 Aug 2012, Sedat Dilek wrote: > Hi, > > this week I was seeing the below NOHZ messages in my logs especially > when suspending and resuming. > > Currently, I am using linux-next (next-20120823) on Ubuntu/precise > AMD64 with a Intel S(a)N(dy)B(ridge)-CPU. > > $ dmesg | grep -A1 -B1 -i nohz > [ 720.331819] Disabling non-boot CPUs ... > [ 720.332035] NOHZ: local_softirq_pending 200 > [ 720.434312] smpboot: CPU 1 is now offline > [ 720.434825] NOHZ: local_softirq_pending 200 > [ 720.538237] smpboot: CPU 2 is now offline > [ 720.538676] NOHZ: local_softirq_pending 200 > [ 720.642162] smpboot: CPU 3 is now offline > > If I manually disable the cpuX... First I did not see NOHZ messages > but then there were some lines seen especially when cpuX went offline > (here: cpu1) > > # echo 0 >/sys/devices/system/cpu/cpu1/online > > [ dmeg ] > [ 2605.515771] smpboot: CPU 1 is now offline > > The same with cpu2 and cpu3. > > Jack Winter confirmed to see similiar NOHZ messages also on > v3.4.9-rt17 kernel (CPU: Core2Duo when no suspend performed): > > [15223.171585] NOHZ: local_softirq_pending 08 That's a different issue. That's a pending networking softirq when we go idle. Unrelated to the RCU / hotplug issue you are observing. > So, the issue is seen on linux-next and -rt kernels. > > According to Thomas "softirq 0x200 is the RCU one" and he requested me > to address the issue to Paul on #linux-rt. > > Regards, > - Sedat - > -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
