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#define sysctl_hung_task_all_cpu_backtrace 0 #endif /* CONFIG_SMP */ +#define TASK_COMM_LEN 16 + 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_check_interval_secs; extern int sysctl_hung_task_warnings; +extern unsigned int sysctl_hung_task_filter_kthread; +extern char sysctl_hung_task_check_comm[TASK_COMM_LEN]; int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); #else diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 396ebaebea3f..e018563d4882 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -23,6 +23,7 @@ #include #include +#include /* * The number of tasks checked: @@ -48,6 +49,16 @@ unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_ */ unsigned long __read_mostly sysctl_hung_task_check_interval_secs; +/* + * Non zero means no checking kthread + */ +unsigned int __read_mostly sysctl_hung_task_filter_kthread = CONFIG_DEFAULT_HUNG_TASK_FILTER_KTHREAD; + +/* + * Only one + */ +char __read_mostly sysctl_hung_task_check_comm[TASK_COMM_LEN] = CONFIG_DEFAULT_HUNG_TASK_CHECK_COMM; + int __read_mostly sysctl_hung_task_warnings = 10; static int __read_mostly did_panic; @@ -88,6 +99,12 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) { unsigned long switch_count = t->nvcsw + t->nivcsw; + if (unlikely(strlen(sysctl_hung_task_check_comm) && !strstr(t->comm, sysctl_hung_task_check_comm))) + return; + + if (unlikely(sysctl_hung_task_filter_kthread && t->flags & PF_KTHREAD)) + return; + /* * Ensure the task is not frozen. * Also, skip vfork and any other user process that freezer should skip. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 62fbd09b5dc1..1daede87c88d 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2519,6 +2519,22 @@ static struct ctl_table kern_table[] = { .proc_handler = proc_dointvec_minmax, .extra1 = &neg_one, }, + { + .procname = "hung_task_filter_kthread", + .data = &sysctl_hung_task_filter_kthread, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "hung_task_check_comm", + .data = &sysctl_hung_task_check_comm, + .maxlen = TASK_COMM_LEN, + .mode = 0644, + .proc_handler = proc_dostring, + }, #endif #ifdef CONFIG_RT_MUTEXES { diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2c7f46b366f1..6eab8cf0c37f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1101,6 +1101,30 @@ config DEFAULT_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 DEFAULT_HUNG_TASK_FILTER_KTHREAD + int "Default filter kthread for hung task" + depends on DETECT_HUNG_TASK + range 0 1 + default 0 + help + This option controls filter kthread used to determine when + a kernel task has become "state=TASK_UNINTERRUPTIBLE" and should be skip. + + It can be adjusted at runtime via the kernel.hung_task_filter_kthread + sysctl or by writing a value to + /proc/sys/kernel/hung_task_filter_kthread. + + A filter of 1 disables the check + +config DEFAULT_HUNG_TASK_CHECK_COMM + string "Default check only one comm" + depends on DETECT_HUNG_TASK + default "" + help + It can be adjusted at runtime via the kernel.hung_task_check_comm + sysctl or by writing a value to + /proc/sys/kernel/hung_task_check_comm. + config BOOTPARAM_HUNG_TASK_PANIC bool "Panic (Reboot) On Hung Tasks" depends on DETECT_HUNG_TASK -- 2.17.1