Re: [PATCH 2/8] mm/zsmalloc: add per class compact trace event
From: Minchan Kim
Date: Sun Jul 03 2016 - 19:48:57 EST
On Fri, Jul 01, 2016 at 02:41:00PM +0800, Ganesh Mahendran wrote:
> add per class compact trace event. It will show how many zs pages
> isolated, how many zs pages reclaimed.
I don't know what you want with this event trace.
What's the relation betwwen the number of zspage isolated and zspage
reclaimed? IOW, with that, what do you want to know?
>
> ----
> <...>-627 [002] .... 192.641122: zs_compact_start: pool zram0
> <...>-627 [002] .... 192.641166: zs_compact_class: class 254: 0 zspage isolated, 0 reclaimed
> <...>-627 [002] .... 192.641169: zs_compact_class: class 202: 0 zspage isolated, 0 reclaimed
> <...>-627 [002] .... 192.641172: zs_compact_class: class 190: 0 zspage isolated, 0 reclaimed
> <...>-627 [002] .... 192.641180: zs_compact_class: class 168: 3 zspage isolated, 1 reclaimed
> <...>-627 [002] .... 192.641190: zs_compact_class: class 151: 3 zspage isolated, 1 reclaimed
> <...>-627 [002] .... 192.641201: zs_compact_class: class 144: 6 zspage isolated, 1 reclaimed
> <...>-627 [002] .... 192.641224: zs_compact_class: class 126: 24 zspage isolated, 12 reclaimed
> <...>-627 [002] .... 192.641261: zs_compact_class: class 111: 10 zspage isolated, 2 reclaimed
> kswapd0-627 [002] .... 192.641333: zs_compact_class: class 107: 38 zspage isolated, 8 reclaimed
> kswapd0-627 [002] .... 192.641415: zs_compact_class: class 100: 45 zspage isolated, 12 reclaimed
> kswapd0-627 [002] .... 192.641481: zs_compact_class: class 94: 24 zspage isolated, 5 reclaimed
> kswapd0-627 [002] .... 192.641568: zs_compact_class: class 91: 69 zspage isolated, 14 reclaimed
> kswapd0-627 [002] .... 192.641688: zs_compact_class: class 83: 120 zspage isolated, 47 reclaimed
> kswapd0-627 [002] .... 192.641765: zs_compact_class: class 76: 34 zspage isolated, 5 reclaimed
> kswapd0-627 [002] .... 192.641832: zs_compact_class: class 74: 34 zspage isolated, 6 reclaimed
> kswapd0-627 [002] .... 192.641958: zs_compact_class: class 71: 66 zspage isolated, 17 reclaimed
> kswapd0-627 [002] .... 192.642000: zs_compact_class: class 67: 17 zspage isolated, 3 reclaimed
> kswapd0-627 [002] .... 192.642063: zs_compact_class: class 66: 29 zspage isolated, 5 reclaimed
> kswapd0-627 [002] .... 192.642113: zs_compact_class: class 62: 38 zspage isolated, 12 reclaimed
> kswapd0-627 [002] .... 192.642143: zs_compact_class: class 58: 8 zspage isolated, 1 reclaimed
> kswapd0-627 [002] .... 192.642176: zs_compact_class: class 57: 25 zspage isolated, 5 reclaimed
> kswapd0-627 [002] .... 192.642184: zs_compact_class: class 54: 11 zspage isolated, 2 reclaimed
> kswapd0-627 [002] .... 192.642191: zs_compact_class: class 52: 5 zspage isolated, 1 reclaimed
> kswapd0-627 [002] .... 192.642201: zs_compact_class: class 51: 6 zspage isolated, 1 reclaimed
> kswapd0-627 [002] .... 192.642211: zs_compact_class: class 49: 11 zspage isolated, 3 reclaimed
> kswapd0-627 [002] .... 192.642216: zs_compact_class: class 46: 2 zspage isolated, 1 reclaimed
> kswapd0-627 [002] .... 192.642218: zs_compact_class: class 44: 0 zspage isolated, 0 reclaimed
> kswapd0-627 [002] .... 192.642221: zs_compact_class: class 43: 0 zspage isolated, 0 reclaimed
> ...
> ----
>
> Signed-off-by: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx>
> ---
> include/trace/events/zsmalloc.h | 24 ++++++++++++++++++++++++
> mm/zsmalloc.c | 16 +++++++++++++++-
> 2 files changed, 39 insertions(+), 1 deletion(-)
>
> diff --git a/include/trace/events/zsmalloc.h b/include/trace/events/zsmalloc.h
> index c7a39f4..e745246 100644
> --- a/include/trace/events/zsmalloc.h
> +++ b/include/trace/events/zsmalloc.h
> @@ -46,6 +46,30 @@ TRACE_EVENT(zs_compact_end,
> __entry->pages_compacted)
> );
>
> +TRACE_EVENT(zs_compact_class,
> +
> + TP_PROTO(int class, unsigned long zspage_isolated, unsigned long zspage_reclaimed),
> +
> + TP_ARGS(class, zspage_isolated, zspage_reclaimed),
> +
> + TP_STRUCT__entry(
> + __field(int, class)
> + __field(unsigned long, zspage_isolated)
> + __field(unsigned long, zspage_reclaimed)
> + ),
> +
> + TP_fast_assign(
> + __entry->class = class;
> + __entry->zspage_isolated = zspage_isolated;
> + __entry->zspage_reclaimed = zspage_reclaimed;
> + ),
> +
> + TP_printk("class %3d: %ld zspage isolated, %ld zspage reclaimed",
> + __entry->class,
> + __entry->zspage_isolated,
> + __entry->zspage_reclaimed)
> +);
> +
> #endif /* _TRACE_ZSMALLOC_H */
>
> /* This part must be outside protection */
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index c7f79d5..405baa5 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -1780,6 +1780,11 @@ struct zs_compact_control {
> /* Starting object index within @s_page which used for live object
> * in the subpage. */
> int index;
> +
> + /* zspage isolated */
> + unsigned long nr_isolated;
> + /* zspage reclaimed */
> + unsigned long nr_reclaimed;
> };
>
> static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
> @@ -2272,7 +2277,10 @@ static unsigned long zs_can_compact(struct size_class *class)
>
> static void __zs_compact(struct zs_pool *pool, struct size_class *class)
> {
> - struct zs_compact_control cc;
> + struct zs_compact_control cc = {
> + .nr_isolated = 0,
> + .nr_reclaimed = 0,
> + };
> struct zspage *src_zspage;
> struct zspage *dst_zspage = NULL;
>
> @@ -2282,10 +2290,13 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class)
> if (!zs_can_compact(class))
> break;
>
> + cc.nr_isolated++;
> +
> cc.index = 0;
> cc.s_page = get_first_page(src_zspage);
>
> while ((dst_zspage = isolate_zspage(class, false))) {
> + cc.nr_isolated++;
> cc.d_page = get_first_page(dst_zspage);
> /*
> * If there is no more space in dst_page, resched
> @@ -2304,6 +2315,7 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class)
> putback_zspage(class, dst_zspage);
> if (putback_zspage(class, src_zspage) == ZS_EMPTY) {
> free_zspage(pool, class, src_zspage);
> + cc.nr_reclaimed++;
> pool->stats.pages_compacted += class->pages_per_zspage;
> }
> spin_unlock(&class->lock);
> @@ -2315,6 +2327,8 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class)
> putback_zspage(class, src_zspage);
>
> spin_unlock(&class->lock);
> +
> + trace_zs_compact_class(class->index, cc.nr_isolated, cc.nr_reclaimed);
> }
>
> unsigned long zs_compact(struct zs_pool *pool)
> --
> 1.9.1
>