diff options
| -rw-r--r-- | Documentation/accounting/delay-accounting.rst | 6 | ||||
| -rw-r--r-- | include/linux/delayacct.h | 4 | ||||
| -rw-r--r-- | kernel/delayacct.c | 36 | ||||
| -rw-r--r-- | kernel/sysctl.c | 12 |
4 files changed, 54 insertions, 4 deletions
diff --git a/Documentation/accounting/delay-accounting.rst b/Documentation/accounting/delay-accounting.rst index f20b282d6de0..1b8b46deeb29 100644 --- a/Documentation/accounting/delay-accounting.rst +++ b/Documentation/accounting/delay-accounting.rst @@ -74,8 +74,10 @@ To enable, add:: delayacct -to the kernel boot options. The rest of the instructions -below assume this has been done. +to the kernel boot options. The rest of the instructions below assume this has +been done. Alternatively, use sysctl kernel.task_delayacct to switch the state +at runtime. Note however that only tasks started after enabling it will have +delayacct information. After the system has booted up, use a utility similar to getdelays.c to access the delays diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 225c8e01a111..af7e6eb50283 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -65,6 +65,10 @@ DECLARE_STATIC_KEY_FALSE(delayacct_key); extern int delayacct_on; /* Delay accounting turned on/off */ extern struct kmem_cache *delayacct_cache; extern void delayacct_init(void); + +extern int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos); + extern void __delayacct_tsk_init(struct task_struct *); extern void __delayacct_tsk_exit(struct task_struct *); extern void __delayacct_blkio_start(void); diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 3f086903b295..51530d5b15a8 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -18,6 +18,17 @@ DEFINE_STATIC_KEY_FALSE(delayacct_key); int delayacct_on __read_mostly; /* Delay accounting turned on/off */ struct kmem_cache *delayacct_cache; +static void set_delayacct(bool enabled) +{ + if (enabled) { + static_branch_enable(&delayacct_key); + delayacct_on = 1; + } else { + delayacct_on = 0; + static_branch_disable(&delayacct_key); + } +} + static int __init delayacct_setup_enable(char *str) { delayacct_on = 1; @@ -29,9 +40,30 @@ void delayacct_init(void) { delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); delayacct_tsk_init(&init_task); - if (delayacct_on) - static_branch_enable(&delayacct_key); + set_delayacct(delayacct_on); +} + +#ifdef CONFIG_PROC_SYSCTL +int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + int state = delayacct_on; + struct ctl_table t; + int err; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + t = *table; + t.data = &state; + err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); + if (err < 0) + return err; + if (write) + set_delayacct(state); + return err; } +#endif void __delayacct_tsk_init(struct task_struct *tsk) { diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 14edf84cc571..0afbfc83157a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -71,6 +71,7 @@ #include <linux/coredump.h> #include <linux/latencytop.h> #include <linux/pid.h> +#include <linux/delayacct.h> #include "../lib/kstrtox.h" @@ -1727,6 +1728,17 @@ static struct ctl_table kern_table[] = { .extra2 = SYSCTL_ONE, }, #endif /* CONFIG_SCHEDSTATS */ +#ifdef CONFIG_TASK_DELAY_ACCT + { + .procname = "task_delayacct", + .data = NULL, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = sysctl_delayacct, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +#endif /* CONFIG_TASK_DELAY_ACCT */ #ifdef CONFIG_NUMA_BALANCING { .procname = "numa_balancing", |