Re: RFC: futex_wait() can DoS the tick

[Mike Galbraith]

On Wed, 2015-06-10 at 17:12 +0200, Thomas Gleixner wrote:

> Some more information about your symptoms in form of configuration,
> extra patches, kernel traces etc. would be appreciated.

homer:~/tmp # perf record -C 3 -eirq:*,irq_vectors:local* -- sleep 10
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 1380.507 MB perf.data (19530595 samples) ]
homer:~/tmp # perf script | grep irq_vectors:local_timer
     ksoftirqd/3    19 [003]  5586.564238: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5586.564239: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5586.568238: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5586.568239: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5586.632218: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5586.632219: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5587.056069: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5587.056071: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5587.307978: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5587.307978: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5588.255633: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5588.255635: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5589.627132: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5589.627133: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5590.334877: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5590.334883: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5590.510815: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5590.510816: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5590.558794: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5590.558796: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5590.822707: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5590.822709: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5592.346152: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5592.346153: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5592.558074: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5592.558076: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5593.741647: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5593.741649: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5594.953208: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5594.953209: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5595.009197: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5595.009198: irq_vectors:local_timer_exit: vector=239
     ksoftirqd/3    19 [003]  5595.397049: irq_vectors:local_timer_entry: vector=239
     ksoftirqd/3    19 [003]  5595.397050: irq_vectors:local_timer_exit: vector=239
 bnc886785_livel  9817 [003]  5595.473025: irq_vectors:local_timer_entry: vector=239
 bnc886785_livel  9817 [003]  5595.473027: irq_vectors:local_timer_exit: vector=239
homer:~/tmp # 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/