* Damien Wyart <[email protected]> wrote:
> * Ingo Molnar <[email protected]> [090216 13:26]:
> > We do get 0x100 which is 1 << RCU_SOFTIRQ, i.e. the RCU softirq. Paul,
> > this indeed seems to be a CONFIG_TREE_RCU=y bug.
>
> > What is weird is that RCU_SOFTIRQ gets set again and again - but there's
> > no raise_softirq() calls. Could you please do a two-CPU trace too via:
>
> > echo 3 > /debug/tracing/tracing_cpumask
>
> > So that we can see what's happening on the other CPU?
>
> > Also, could you please apply the debug patch below (or update to the
> > very latest -tip tree), so that we get trace entries of softirq triggers
> > too?
>
> Ok, the new trace with these additional modifications is here:
> http://damien.wyart.free.fr/ksoftirqd_pb/trace_tip_2009.02.16_1300_ksoftirqd_pb_abstime_proc_mask3.txt.gz
thanks.
This confirms that SOFTIRQ_RCU gets raised here in the timer IRQ:
136.255963 | 0) sleep-2345 | |
update_process_times() {
136.255964 | 0) sleep-2345 | |
account_process_tick() {
136.255965 | 0) sleep-2345 | 0.779 us |
account_system_time();
136.255966 | 0) sleep-2345 | 2.262 us | }
136.255967 | 0) sleep-2345 | |
run_local_timers() {
136.255968 | 0) sleep-2345 | 0.802 us |
hrtimer_run_queues();
136.255969 | 0) sleep-2345 | |
raise_softirq() {
136.255970 | 0) sleep-2345 | |
raise_softirq_irqoff() {
136.255971 | 0) sleep-2345 | |
__raise_softirq_irqoff() {
136.255972 | 0) sleep-2345 | | /* nr:
1 */
136.255973 | 0) sleep-2345 | 2.194 us | }
136.255974 | 0) sleep-2345 | 3.832 us | }
136.255975 | 0) sleep-2345 | 5.491 us | }
136.255976 | 0) sleep-2345 | 8.667 us | }
136.255976 | 0) sleep-2345 | 0.792 us | rcu_pending();
136.255978 | 0) sleep-2345 | |
rcu_check_callbacks() {
136.255979 | 0) sleep-2345 | 0.781 us | idle_cpu();
136.255981 | 0) sleep-2345 | |
raise_softirq() {
136.255981 | 0) sleep-2345 | |
raise_softirq_irqoff() {
136.255982 | 0) sleep-2345 | |
__raise_softirq_irqoff() {
136.255983 | 0) sleep-2345 | | /* nr:
8 */
136.255984 | 0) sleep-2345 | 1.555 us | }
136.255984 | 0) sleep-2345 | 3.059 us | }
136.255985 | 0) sleep-2345 | 4.594 us | }
136.255986 | 0) sleep-2345 | 7.800 us | }
136.255987 | 0) sleep-2345 | 0.737 us | printk_tick();
again and again.
Ingo
--
To unsubscribe from this list: send the line "unsubscribe kernel-testers" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
