On Sat, Dec 04, 2021 at 04:09:55AM -0800, yongw.pur@xxxxxxxxx wrote:
> From: wangyong <wang.yong12@xxxxxxxxxx>
>
> Delay accounting does not track the delay of memory compact.
> When there is not enough free memory, tasks can spend
> a amount of their time waiting for compact.
>
> To get the impact of tasks in direct memory compact, measure
> the delay when allocating memory through memory compact.
>
Should we call this DIRECT_COMPACT and through documentation
or name change imply that this won't work for kcompactd the
kernel thread - based on my reading of the patches.
> Also update tools/accounting/getdelays.c:
> / # ./getdelays_next -di -p 304
> print delayacct stats ON
> printing IO accounting
> PID 304
>
> CPU count real total virtual total delay total delay average
> 277 780000000 849039485 18877296 0.068ms
> IO count delay total delay average
> 0 0 0ms
> SWAP count delay total delay average
> 0 0 0ms
> RECLAIM count delay total delay average
> 5 11088812685 2217ms
> THRASHING count delay total delay average
> 0 0 0ms
> COMPACT count delay total delay average
> 3 72758 0ms
> watch: read=0, write=0, cancelled_write=0
>
> Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: wangyong <wang.yong12@xxxxxxxxxx>
> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Jiang Xuexin <jiang.xuexin@xxxxxxxxxx>
> Reviewed-by: Zhang Wenya <zhang.wenya1@xxxxxxxxxx>
> Reviewed-by: Yang Yang <yang.yang29@xxxxxxxxxx>
> ---
>
> Changes since v1:
> -fixed duplicate member freepages_start.
>
> include/linux/delayacct.h | 28 ++++++++++++++++++++++++++++
> include/uapi/linux/taskstats.h | 6 +++++-
> kernel/delayacct.c | 15 +++++++++++++++
> mm/page_alloc.c | 3 +++
> tools/accounting/getdelays.c | 8 +++++++-
> 5 files changed, 58 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
> index 435c365..3e03d01 100644
> --- a/include/linux/delayacct.h
> +++ b/include/linux/delayacct.h
> @@ -42,8 +42,12 @@ struct task_delay_info {
> u64 thrashing_start;
> u64 thrashing_delay; /* wait for thrashing page */
>
> + u64 compact_start;
> + u64 compact_delay; /* wait for memory compact */
> +
> u32 freepages_count; /* total count of memory reclaim */
> u32 thrashing_count; /* total count of thrash waits */
> + u32 compact_count; /* total count of memory compact */
> };
> #endif
>
> @@ -72,6 +76,8 @@ 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);
>
> static inline void delayacct_tsk_init(struct task_struct *tsk)
> {
> @@ -170,6 +176,24 @@ static inline void delayacct_swapin_end(void)
> __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();
> +}
> +
> #else
> static inline void delayacct_init(void)
> {}
> @@ -200,6 +224,10 @@ 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)
> +{}
>
> #endif /* CONFIG_TASK_DELAY_ACCT */
>
> diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h
> index ccbd087..12327d3 100644
> --- a/include/uapi/linux/taskstats.h
> +++ b/include/uapi/linux/taskstats.h
> @@ -34,7 +34,7 @@
> */
>
>
> -#define TASKSTATS_VERSION 10
> +#define TASKSTATS_VERSION 11
> #define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN
> * in linux/sched.h */
>
> @@ -172,6 +172,10 @@ struct taskstats {
>
> /* v10: 64-bit btime to avoid overflow */
> __u64 ac_btime64; /* 64-bit begin time */
> +
> + /* Delay waiting for memory compact */
> + __u64 compact_count;
> + __u64 compact_delay_total;
> };
>
>
> diff --git a/kernel/delayacct.c b/kernel/delayacct.c
> index 11f3cd8..c5e8cea 100644
> --- a/kernel/delayacct.c
> +++ b/kernel/delayacct.c
> @@ -155,10 +155,13 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
> d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
> tmp = d->thrashing_delay_total + tsk->delays->thrashing_delay;
> 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;
> 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;
> raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
>
> return 0;
> @@ -214,3 +217,15 @@ void __delayacct_swapin_end(void)
> ¤t->delays->swapin_count);
> }
>
> +void __delayacct_compact_start(void)
> +{
> + current->delays->compact_start = local_clock();
> +}
> +
> +void __delayacct_compact_end(void)
> +{
> + delayacct_end(¤t->delays->lock,
> + ¤t->delays->compact_start,
> + ¤t->delays->compact_delay,
> + ¤t->delays->compact_count);
> +}
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index edfd6c8..6430226 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -74,6 +74,7 @@
> #include <linux/padata.h>
> #include <linux/khugepaged.h>
> #include <linux/buffer_head.h>
> +#include <linux/delayacct.h>
> #include <asm/sections.h>
> #include <asm/tlbflush.h>
> #include <asm/div64.h>
> @@ -4363,6 +4364,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
> return NULL;
>
> psi_memstall_enter(&pflags);
> + delayacct_compact_start();
> noreclaim_flag = memalloc_noreclaim_save();
>
> *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
> @@ -4370,6 +4372,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
>
> memalloc_noreclaim_restore(noreclaim_flag);
> psi_memstall_leave(&pflags);
> + delayacct_compact_end();
>
> if (*compact_result == COMPACT_SKIPPED)
> return NULL;
> diff --git a/tools/accounting/getdelays.c b/tools/accounting/getdelays.c
> index 5ef1c15..11e8673 100644
> --- a/tools/accounting/getdelays.c
> +++ b/tools/accounting/getdelays.c
> @@ -205,6 +205,8 @@ static void print_delayacct(struct taskstats *t)
> "RECLAIM %12s%15s%15s\n"
> " %15llu%15llu%15llums\n"
> "THRASHING%12s%15s%15s\n"
> + " %15llu%15llu%15llums\n"
> + "COMPACT %12s%15s%15s\n"
> " %15llu%15llu%15llums\n",
> "count", "real total", "virtual total",
> "delay total", "delay average",
> @@ -228,7 +230,11 @@ static void print_delayacct(struct taskstats *t)
> "count", "delay total", "delay average",
> (unsigned long long)t->thrashing_count,
> (unsigned long long)t->thrashing_delay_total,
> - average_ms(t->thrashing_delay_total, t->thrashing_count));
> + average_ms(t->thrashing_delay_total, t->thrashing_count),
> + "count", "delay total", "delay average",
> + (unsigned long long)t->compact_count,
> + (unsigned long long)t->compact_delay_total,
> + average_ms(t->compact_delay_total, t->compact_count));
> }
>
> static void task_context_switch_counts(struct taskstats *t)
> --
> 2.7.4
>
At some point we should make the user space tool version aware.
Reviewed-by: Balbir Singh <bsingharora@xxxxxxxxx>
