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/* SPDX-License-Identifier: GPL-2.0-or-later */
/* delayacct.h - per-task delay accounting
*
* Copyright (C) Shailabh Nagar, IBM Corp. 2006
*/
#ifndef _LINUX_DELAYACCT_H
#define _LINUX_DELAYACCT_H
#include <uapi/linux/taskstats.h>
/*
* Per-task flags relevant to delay accounting
* maintained privately to avoid exhausting similar flags in sched.h:PF_*
* Used to set current->delays->flags
*/
#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
#define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */
#ifdef CONFIG_TASK_DELAY_ACCT
struct task_delay_info {
raw_spinlock_t lock;
unsigned int flags; /* Private per-task flags */
/* For each stat XXX, add following, aligned appropriately
*
* struct timespec XXX_start, XXX_end;
* u64 XXX_delay;
* u32 XXX_count;
*
* Atomicity of updates to XXX_delay, XXX_count protected by
* single lock above (split into XXX_lock if contention is an issue).
*/
/*
* XXX_count is incremented on every XXX operation, the delay
* associated with the operation is added to XXX_delay.
* XXX_delay contains the accumulated delay time in nanoseconds.
*/
u64 blkio_start; /* Shared by blkio, swapin */
u64 blkio_delay; /* wait for sync block io completion */
u64 swapin_delay; /* wait for swapin block io completion */
u32 blkio_count; /* total count of the number of sync block */
/* io operations performed */
u32 swapin_count; /* total count of the number of swapin block */
/* io operations performed */
u64 freepages_start;
u64 freepages_delay; /* wait for memory reclaim */
u64 thrashing_start;
u64 thrashing_delay; /* wait for thrashing page */
u32 freepages_count; /* total count of memory reclaim */
u32 thrashing_count; /* total count of thrash waits */
};
#endif
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/jump_label.h>
#ifdef CONFIG_TASK_DELAY_ACCT
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);
extern void __delayacct_blkio_end(struct task_struct *);
extern int delayacct_add_tsk(struct taskstats *, struct task_struct *);
extern __u64 __delayacct_blkio_ticks(struct task_struct *);
extern void __delayacct_freepages_start(void);
extern void __delayacct_freepages_end(void);
extern void __delayacct_thrashing_start(void);
extern void __delayacct_thrashing_end(void);
static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
{
if (p->delays)
return (p->delays->flags & DELAYACCT_PF_BLKIO);
else
return 0;
}
static inline void delayacct_set_flag(struct task_struct *p, int flag)
{
if (p->delays)
p->delays->flags |= flag;
}
static inline void delayacct_clear_flag(struct task_struct *p, int flag)
{
if (p->delays)
p->delays->flags &= ~flag;
}
static inline void delayacct_tsk_init(struct task_struct *tsk)
{
/* reinitialize in case parent's non-null pointer was dup'ed*/
tsk->delays = NULL;
if (delayacct_on)
__delayacct_tsk_init(tsk);
}
/* Free tsk->delays. Called from bad fork and __put_task_struct
* where there's no risk of tsk->delays being accessed elsewhere
*/
static inline void delayacct_tsk_free(struct task_struct *tsk)
{
if (tsk->delays)
kmem_cache_free(delayacct_cache, tsk->delays);
tsk->delays = NULL;
}
static inline void delayacct_blkio_start(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
delayacct_set_flag(current, DELAYACCT_PF_BLKIO);
if (current->delays)
__delayacct_blkio_start();
}
static inline void delayacct_blkio_end(struct task_struct *p)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (p->delays)
__delayacct_blkio_end(p);
delayacct_clear_flag(p, DELAYACCT_PF_BLKIO);
}
static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
{
if (tsk->delays)
return __delayacct_blkio_ticks(tsk);
return 0;
}
static inline void delayacct_freepages_start(void)
{
if (current->delays)
__delayacct_freepages_start();
}
static inline void delayacct_freepages_end(void)
{
if (current->delays)
__delayacct_freepages_end();
}
static inline void delayacct_thrashing_start(void)
{
if (current->delays)
__delayacct_thrashing_start();
}
static inline void delayacct_thrashing_end(void)
{
if (current->delays)
__delayacct_thrashing_end();
}
#else
static inline void delayacct_set_flag(struct task_struct *p, int flag)
{}
static inline void delayacct_clear_flag(struct task_struct *p, int flag)
{}
static inline void delayacct_init(void)
{}
static inline void delayacct_tsk_init(struct task_struct *tsk)
{}
static inline void delayacct_tsk_free(struct task_struct *tsk)
{}
static inline void delayacct_blkio_start(void)
{}
static inline void delayacct_blkio_end(struct task_struct *p)
{}
static inline int delayacct_add_tsk(struct taskstats *d,
struct task_struct *tsk)
{ return 0; }
static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
{ return 0; }
static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
{ return 0; }
static inline void delayacct_freepages_start(void)
{}
static inline void delayacct_freepages_end(void)
{}
static inline void delayacct_thrashing_start(void)
{}
static inline void delayacct_thrashing_end(void)
{}
#endif /* CONFIG_TASK_DELAY_ACCT */
#endif
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