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Commit 68d3f1d810500e8b975bdf0b20dd83d060076b4b

Authored by Don Zickus
Committed by Ingo Molnar
1 parent 3aaba20f26
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

lockup_detector: Sync touch_*_watchdog back to old semantics 

During my rewrite, the semantics of touch_nmi_watchdog and
touch_softlockup_watchdog changed enough to break some drivers
(mostly over preemptable regions).

These are cases where long delays on one CPU (due to
print_delay for example) can cause long delays on other
CPUs - so we must 'touch' the nmi_watchdog flag of those
other CPUs as well.

This change brings those touch_*_watchdog() functions back in line
with to how they used to work.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: peterz@infradead.org
Cc: fweisbec@gmail.com
LKML-Reference: <1283310009-22168-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Showing 1 changed file with 12 additions and 5 deletions Side-by-side Diff

... ... @@ -122,7 +122,7 @@
122 122  
123 123 void touch_softlockup_watchdog(void)
124 124 {
125   - __get_cpu_var(watchdog_touch_ts) = 0;
  125 + __raw_get_cpu_var(watchdog_touch_ts) = 0;
126 126 }
127 127 EXPORT_SYMBOL(touch_softlockup_watchdog);
128 128  
... ... @@ -142,7 +142,14 @@
142 142 #ifdef CONFIG_HARDLOCKUP_DETECTOR
143 143 void touch_nmi_watchdog(void)
144 144 {
145   - __get_cpu_var(watchdog_nmi_touch) = true;
  145 + if (watchdog_enabled) {
  146 + unsigned cpu;
  147 +
  148 + for_each_present_cpu(cpu) {
  149 + if (per_cpu(watchdog_nmi_touch, cpu) != true)
  150 + per_cpu(watchdog_nmi_touch, cpu) = true;
  151 + }
  152 + }
146 153 touch_softlockup_watchdog();
147 154 }
148 155 EXPORT_SYMBOL(touch_nmi_watchdog);
... ... @@ -433,6 +440,9 @@
433 440 wake_up_process(p);
434 441 }
435 442  
  443 + /* if any cpu succeeds, watchdog is considered enabled for the system */
  444 + watchdog_enabled = 1;
  445 +
436 446 return 0;
437 447 }
438 448  
... ... @@ -455,9 +465,6 @@
455 465 per_cpu(softlockup_watchdog, cpu) = NULL;
456 466 kthread_stop(p);
457 467 }
458   -
459   - /* if any cpu succeeds, watchdog is considered enabled for the system */
460   - watchdog_enabled = 1;
461 468 }
462 469  
463 470 static void watchdog_enable_all_cpus(void)