From a3d5dc908a5f572ce3e31fe83fd2459a1c3c5422 Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Wed, 19 Jan 2022 18:10:02 -0800 Subject: delayacct: support swapin delay accounting for swapping without blkio 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 Reported-by: Zeal Robot Cc: Balbir Singh Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/delayacct.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) (limited to 'kernel/delayacct.c') diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 51530d5b15a8..97699848c1f0 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -100,19 +100,10 @@ void __delayacct_blkio_start(void) */ void __delayacct_blkio_end(struct task_struct *p) { - struct task_delay_info *delays = p->delays; - u64 *total; - u32 *count; - - if (p->delays->flags & DELAYACCT_PF_SWAPIN) { - total = &delays->swapin_delay; - count = &delays->swapin_count; - } else { - total = &delays->blkio_delay; - count = &delays->blkio_count; - } - - delayacct_end(&delays->lock, &delays->blkio_start, total, count); + delayacct_end(&p->delays->lock, + &p->delays->blkio_start, + &p->delays->blkio_delay, + &p->delays->blkio_count); } int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) @@ -179,8 +170,7 @@ __u64 __delayacct_blkio_ticks(struct task_struct *tsk) unsigned long flags; raw_spin_lock_irqsave(&tsk->delays->lock, flags); - ret = nsec_to_clock_t(tsk->delays->blkio_delay + - tsk->delays->swapin_delay); + ret = nsec_to_clock_t(tsk->delays->blkio_delay); raw_spin_unlock_irqrestore(&tsk->delays->lock, flags); return ret; } @@ -210,3 +200,16 @@ void __delayacct_thrashing_end(void) ¤t->delays->thrashing_delay, ¤t->delays->thrashing_count); } + +void __delayacct_swapin_start(void) +{ + current->delays->swapin_start = local_clock(); +} + +void __delayacct_swapin_end(void) +{ + delayacct_end(¤t->delays->lock, + ¤t->delays->swapin_start, + ¤t->delays->swapin_delay, + ¤t->delays->swapin_count); +} -- cgit v1.2.3