watchdog, hung_task_timeout: Add Kconfig configurable default

This patch allows the default value for sysctl_hung_task_timeout_secs to be set at build time. The feature carries virtually no overhead, so it makes sense to keep it enabled. On heavily loaded systems, though, it can end up triggering stack traces when there is no bug other than the system being underprovisioned. We use this patch to keep the hung task facility available but disabled at boot-time. The default of 120 seconds is preserved. As a note, commit e162b39a may have accidentally reverted commit fb822db4, which raised the default from 120 seconds to 480 seconds. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Mandeep Singh Baines <msb@google.com> Link: http://lkml.kernel.org/r/4DB8600C.8080000@suse.com Signed-off-by: Ingo Molnar <mingo@elte.hu>

watchdog, hung_task_timeout: Add Kconfig configurable default
This patch allows the default value for sysctl_hung_task_timeout_secs to be set at build time. The feature carries virtually no overhead, so it makes sense to keep it enabled. On heavily loaded systems, though, it can end up triggering stack traces when there is no bug other than the system being underprovisioned. We use this patch to keep the hung task facility available but disabled at boot-time. The default of 120 seconds is preserved. As a note, commit e162b39a may have accidentally reverted commit fb822db4, which raised the default from 120 seconds to 480 seconds. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Mandeep Singh Baines <msb@google.com> Link: http://lkml.kernel.org/r/4DB8600C.8080000@suse.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jeff Mahoney · Ingo Molnar
1 parent e0944ee63f
Showing 2 changed files with 16 additions and 1 deletions Side-by-side Diff
kernel/hung_task.c
lib/Kconfig.debug
@@ -33,7 +33,7 @@
 /*
  * Zero means infinite timeout - no checking done:
  */
-unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;
+unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT;
  
 unsigned long __read_mostly sysctl_hung_task_warnings = 10;
  
@@ -238,6 +238,21 @@
 	  enabled then all held locks will also be reported. This
 	  feature has negligible overhead.
  
+config DEFAULT_HUNG_TASK_TIMEOUT
+	int "Default timeout for hung task detection (in seconds)"
+	depends on DETECT_HUNG_TASK
+	default 120
+	help
+	  This option controls the default timeout (in seconds) used
+	  to determine when a task has become non-responsive and should
+	  be considered hung.
+
+	  It can be adjusted at runtime via the kernel.hung_task_timeout
+	  sysctl or by writing a value to /proc/sys/kernel/hung_task_timeout.
+
+	  A timeout of 0 disables the check.  The default is two minutes.
+	  Keeping the default should be fine in most cases.
+
 config BOOTPARAM_HUNG_TASK_PANIC
 	bool "Panic (Reboot) On Hung Tasks"
 	depends on DETECT_HUNG_TASK
...	...	@@ -33,7 +33,7 @@
33	33	/*
34	34	* Zero means infinite timeout - no checking done:
35	35	*/
36		-unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;
	36	+unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT;
37	37
38	38	unsigned long __read_mostly sysctl_hung_task_warnings = 10;
39	39
...	...	@@ -238,6 +238,21 @@
238	238	enabled then all held locks will also be reported. This
239	239	feature has negligible overhead.
240	240
	241	+config DEFAULT_HUNG_TASK_TIMEOUT
	242	+ int "Default timeout for hung task detection (in seconds)"
	243	+ depends on DETECT_HUNG_TASK
	244	+ default 120
	245	+ help
	246	+ This option controls the default timeout (in seconds) used
	247	+ to determine when a task has become non-responsive and should
	248	+ be considered hung.
	249	+
	250	+ It can be adjusted at runtime via the kernel.hung_task_timeout
	251	+ sysctl or by writing a value to /proc/sys/kernel/hung_task_timeout.
	252	+
	253	+ A timeout of 0 disables the check. The default is two minutes.
	254	+ Keeping the default should be fine in most cases.
	255	+
241	256	config BOOTPARAM_HUNG_TASK_PANIC
242	257	bool "Panic (Reboot) On Hung Tasks"
243	258	depends on DETECT_HUNG_TASK