From 1186618a6a35d43a865448472a261184b608d13c Mon Sep 17 00:00:00 2001 From: tangmeng Date: Fri, 18 Feb 2022 18:59:36 +0800 Subject: kernel/delayacct: move delayacct sysctls to its own file kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. All filesystem syctls now get reviewed by fs folks. This commit follows the commit of fs, move the delayacct sysctl to its own file, kernel/delayacct.c. Signed-off-by: tangmeng Signed-off-by: Luis Chamberlain --- kernel/delayacct.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'kernel/delayacct.c') diff --git a/kernel/delayacct.c b/kernel/delayacct.c index c5e8cea9e05f..2c1e18f7c5cf 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -44,7 +44,7 @@ void delayacct_init(void) } #ifdef CONFIG_PROC_SYSCTL -int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, +static int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { int state = delayacct_on; @@ -63,6 +63,26 @@ int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, set_delayacct(state); return err; } + +static struct ctl_table kern_delayacct_table[] = { + { + .procname = "task_delayacct", + .data = NULL, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = sysctl_delayacct, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { } +}; + +static __init int kernel_delayacct_sysctls_init(void) +{ + register_sysctl_init("kernel", kern_delayacct_table); + return 0; +} +late_initcall(kernel_delayacct_sysctls_init); #endif void __delayacct_tsk_init(struct task_struct *tsk) -- cgit v1.2.3 From 662ce1dc9caf493c309200edbe38d186f1ea20d0 Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Wed, 1 Jun 2022 15:55:25 -0700 Subject: 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 Reviewed-by: David Hildenbrand Reviewed-by: Jiang Xuexin Reviewed-by: Ran Xiaokai Reviewed-by: wangyong Cc: Jonathan Corbet Cc: Balbir Singh Cc: Mike Kravetz Cc: Stephen Rothwell Signed-off-by: Andrew Morton --- kernel/delayacct.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'kernel/delayacct.c') diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 2c1e18f7c5cf..164ed9ef77a3 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -177,11 +177,14 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp; tmp = d->compact_delay_total + tsk->delays->compact_delay; d->compact_delay_total = (tmp < d->compact_delay_total) ? 0 : tmp; + tmp = d->wpcopy_delay_total + tsk->delays->wpcopy_delay; + d->wpcopy_delay_total = (tmp < d->wpcopy_delay_total) ? 0 : tmp; d->blkio_count += tsk->delays->blkio_count; d->swapin_count += tsk->delays->swapin_count; d->freepages_count += tsk->delays->freepages_count; d->thrashing_count += tsk->delays->thrashing_count; d->compact_count += tsk->delays->compact_count; + d->wpcopy_count += tsk->delays->wpcopy_count; raw_spin_unlock_irqrestore(&tsk->delays->lock, flags); return 0; @@ -249,3 +252,16 @@ void __delayacct_compact_end(void) ¤t->delays->compact_delay, ¤t->delays->compact_count); } + +void __delayacct_wpcopy_start(void) +{ + current->delays->wpcopy_start = local_clock(); +} + +void __delayacct_wpcopy_end(void) +{ + delayacct_end(¤t->delays->lock, + ¤t->delays->wpcopy_start, + ¤t->delays->wpcopy_delay, + ¤t->delays->wpcopy_count); +} -- cgit v1.2.3