diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 6d486404200e..4205f3c05cbe 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -33,6 +33,10 @@ show up in /proc/sys/kernel: - domainname - hostname - hotplug +- hung_task_panic +- hung_task_check_count +- hung_task_timeout_secs +- hung_task_warnings - kptr_restrict - kstack_depth_to_print [ X86 only ] - l2cr [ PPC only ] @@ -287,6 +291,44 @@ Default value is "/sbin/hotplug". ============================================================== +hung_task_panic: + +Controls the kernel's behavior when a hung task is detected. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +0: continue operation. This is the default behavior. + +1: panic immediately. + +============================================================== + +hung_task_check_count: + +The upper bound on the number of tasks that are checked. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +============================================================== + +hung_task_timeout_secs: + +Check interval. When a task in D state did not get scheduled +for more than this value report a warning. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +0: means infinite timeout - no checking done. + +============================================================== + +hung_task_warning: + +The maximum number of warnings to report. During a check interval +When this value is reached, no more the warnings will be reported. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +-1: report an infinite number of warnings. + +============================================================== + kptr_restrict: This toggle indicates whether restrictions are placed on diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index 31e0193cb0c5..3a93f842306a 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -5,7 +5,7 @@ extern int sysctl_hung_task_check_count; extern unsigned int sysctl_hung_task_panic; extern unsigned long sysctl_hung_task_timeout_secs; -extern unsigned long sysctl_hung_task_warnings; +extern int sysctl_hung_task_warnings; extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 9328b80eaf14..0b9c169d577f 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -37,7 +37,7 @@ int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT; */ unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT; -unsigned long __read_mostly sysctl_hung_task_warnings = 10; +int __read_mostly sysctl_hung_task_warnings = 10; static int __read_mostly did_panic; @@ -98,7 +98,9 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) if (!sysctl_hung_task_warnings) return; - sysctl_hung_task_warnings--; + + if (sysctl_hung_task_warnings > 0) + sysctl_hung_task_warnings--; /* * Ok, the task did not get scheduled for more than 2 minutes, diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c398a58673a7..dd5b4496637e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -122,7 +122,8 @@ extern int blk_iopoll_enabled; static int sixty = 60; #endif -static int neg_one = -1; +static int __maybe_unused neg_one = -1; + static int zero; static int __maybe_unused one = 1; static int __maybe_unused two = 2; @@ -978,9 +979,10 @@ static struct ctl_table kern_table[] = { { .procname = "hung_task_warnings", .data = &sysctl_hung_task_warnings, - .maxlen = sizeof(unsigned long), + .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_doulongvec_minmax, + .proc_handler = proc_dointvec_minmax, + .extra1 = &neg_one, }, #endif #ifdef CONFIG_COMPAT