linux-stable/include/linux/delayacct.h
Yang Yang 662ce1dc9c delayacct: track delays from write-protect copy
Delay accounting does not track the delay of write-protect copy.  When
tasks trigger many write-protect copys(include COW and unsharing of
anonymous pages[1]), it may spend a amount of time waiting for them.  To
get the delay of tasks in write-protect copy, could help users to evaluate
the impact of using KSM or fork() or GUP.

Also update tools/accounting/getdelays.c:

    / # ./getdelays -dl -p 231
    print delayacct stats ON
    listen forever
    PID     231

    CPU             count     real total  virtual total    delay total  delay average
                     6247     1859000000     2154070021     1674255063          0.268ms
    IO              count    delay total  delay average
                        0              0              0ms
    SWAP            count    delay total  delay average
                        0              0              0ms
    RECLAIM         count    delay total  delay average
                        0              0              0ms
    THRASHING       count    delay total  delay average
                        0              0              0ms
    COMPACT         count    delay total  delay average
                        3          72758              0ms
    WPCOPY          count    delay total  delay average
                     3635      271567604              0ms

[1] commit 31cc5bc4af70("mm: support GUP-triggered unsharing of anonymous pages")

Link: https://lkml.kernel.org/r/20220409014342.2505532-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jiang Xuexin <jiang.xuexin@zte.com.cn>
Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: wangyong <wang.yong12@zte.com.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-01 15:55:25 -07:00

259 lines
6.3 KiB
C

/* 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>
#ifdef CONFIG_TASK_DELAY_ACCT
struct task_delay_info {
raw_spinlock_t lock;
/* 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;
u64 blkio_delay; /* wait for sync block io completion */
u64 swapin_start;
u64 swapin_delay; /* wait for swapin */
u32 blkio_count; /* total count of the number of sync block */
/* io operations performed */
u32 swapin_count; /* total count of swapin */
u64 freepages_start;
u64 freepages_delay; /* wait for memory reclaim */
u64 thrashing_start;
u64 thrashing_delay; /* wait for thrashing page */
u64 compact_start;
u64 compact_delay; /* wait for memory compact */
u64 wpcopy_start;
u64 wpcopy_delay; /* wait for write-protect copy */
u32 freepages_count; /* total count of memory reclaim */
u32 thrashing_count; /* total count of thrash waits */
u32 compact_count; /* total count of memory compact */
u32 wpcopy_count; /* total count of write-protect copy */
};
#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 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);
extern void __delayacct_swapin_start(void);
extern void __delayacct_swapin_end(void);
extern void __delayacct_compact_start(void);
extern void __delayacct_compact_end(void);
extern void __delayacct_wpcopy_start(void);
extern void __delayacct_wpcopy_end(void);
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;
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);
}
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 (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_freepages_start();
}
static inline void delayacct_freepages_end(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_freepages_end();
}
static inline void delayacct_thrashing_start(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_thrashing_start();
}
static inline void delayacct_thrashing_end(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_thrashing_end();
}
static inline void delayacct_swapin_start(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_swapin_start();
}
static inline void delayacct_swapin_end(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_swapin_end();
}
static inline void delayacct_compact_start(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_compact_start();
}
static inline void delayacct_compact_end(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_compact_end();
}
static inline void delayacct_wpcopy_start(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_wpcopy_start();
}
static inline void delayacct_wpcopy_end(void)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
__delayacct_wpcopy_end();
}
#else
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)
{}
static inline void delayacct_swapin_start(void)
{}
static inline void delayacct_swapin_end(void)
{}
static inline void delayacct_compact_start(void)
{}
static inline void delayacct_compact_end(void)
{}
static inline void delayacct_wpcopy_start(void)
{}
static inline void delayacct_wpcopy_end(void)
{}
#endif /* CONFIG_TASK_DELAY_ACCT */
#endif