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delayacct: support swapin delay accounting for swapping without blkio

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Currently delayacct accounts swapin delay only for swapping that cause
blkio.  If we use zram for swapping, tools/accounting/getdelays can't
get any SWAP delay.

It's useful to get zram swapin delay information, for example to adjust
compress algorithm or /proc/sys/vm/swappiness.

Reference to PSI, it accounts any kind of swapping by doing its work in
swap_readpage(), no matter whether swapping causes blkio.  Let delayacct
do the similar work.

Link: https://lkml.kernel.org/r/20211112083813.8559-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yang Yang
2022-01-19 18:10:02 -08:00
committed by Linus Torvalds
parent e83a4472bf
commit a3d5dc908a
4 changed files with 43 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
include/linux/delayacct.h
View File

@@ -9,14 +9,6 @@
#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;
@@ -37,13 +29,13 @@ struct task_delay_info {
* 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_start;
u64 blkio_delay; /* wait for sync block io completion */
u64 swapin_delay; /* wait for swapin 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 the number of swapin block */
/* io operations performed */
u32 swapin_count; /* total count of swapin */
u64 freepages_start;
u64 freepages_delay; /* wait for memory reclaim */
@@ -79,14 +71,8 @@ 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;
}
extern void __delayacct_swapin_start(void);
extern void __delayacct_swapin_end(void);
static inline void delayacct_set_flag(struct task_struct *p, int flag)
{
@@ -123,7 +109,6 @@ 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();
}
@@ -135,7 +120,6 @@ static inline void delayacct_blkio_end(struct task_struct *p)
if (p->delays)
__delayacct_blkio_end(p);
delayacct_clear_flag(p, DELAYACCT_PF_BLKIO);
}
static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
@@ -169,6 +153,18 @@ static inline void delayacct_thrashing_end(void)
__delayacct_thrashing_end();
}
static inline void delayacct_swapin_start(void)
{
if (current->delays)
__delayacct_swapin_start();
}
static inline void delayacct_swapin_end(void)
{
if (current->delays)
__delayacct_swapin_end();
}
#else
static inline void delayacct_set_flag(struct task_struct *p, int flag)
{}
@@ -199,6 +195,10 @@ 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)
{}
#endif /* CONFIG_TASK_DELAY_ACCT */