Re: [PATCH 5/9] mm/page_alloc: inline __rmqueue_pcplist

[Vlastimil Babka]

On 3/25/21 12:42 PM, Mel Gorman wrote:
> From: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> 
> When __alloc_pages_bulk() got introduced two callers of __rmqueue_pcplist
> exist and the compiler chooses to not inline this function.
> 
>  ./scripts/bloat-o-meter vmlinux-before vmlinux-inline__rmqueue_pcplist
> add/remove: 0/1 grow/shrink: 2/0 up/down: 164/-125 (39)
> Function                                     old     new   delta
> rmqueue                                     2197    2296     +99
> __alloc_pages_bulk                          1921    1986     +65
> __rmqueue_pcplist                            125       -    -125
> Total: Before=19374127, After=19374166, chg +0.00%
> 
> modprobe page_bench04_bulk loops=$((10**7))
> 
> Type:time_bulk_page_alloc_free_array
>  -  Per elem: 106 cycles(tsc) 29.595 ns (step:64)
>  - (measurement period time:0.295955434 sec time_interval:295955434)
>  - (invoke count:10000000 tsc_interval:1065447105)
> 
> Before:
>  - Per elem: 110 cycles(tsc) 30.633 ns (step:64)
> 
> Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> ---
>  mm/page_alloc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 1ec18121268b..d900e92884b2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3415,7 +3415,8 @@ static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
>  }
>  
>  /* Remove page from the per-cpu list, caller must protect the list */
> -static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
> +static inline
> +struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
>  			unsigned int alloc_flags,
>  			struct per_cpu_pages *pcp,
>  			struct list_head *list)
>