Re: [PATCH v2] mm: Simplify shrink_inactive_list()

[Michal Hocko <mhocko@suse.com>]

On Fri 12-04-19 14:33:27, Kirill Tkhai wrote:
> On 12.04.2019 14:31, Michal Hocko wrote:
> > On Fri 12-04-19 13:55:59, Kirill Tkhai wrote:
> >> This merges together duplicating patterns of code.
> > 
> > OK, this looks better than the previous version
> > 
> >> Also, replace count_memcg_events() with its
> >> irq-careless namesake.
> > 
> > Why?
> 
> Since interrupts are already disabled, and there is
> no a sense to disable them twice.

right and changelog could have mentioned that...

> >> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>

Anyway, forgot to add
Acked-by: Michal Hocko <mhocko@suse.com>

> >>
> >> v2: Introduce local variable.
> >> ---
> >>  mm/vmscan.c |   31 +++++++++----------------------
> >>  1 file changed, 9 insertions(+), 22 deletions(-)
> >>
> >> diff --git a/mm/vmscan.c b/mm/vmscan.c
> >> index 836b28913bd7..d96efff59a11 100644
> >> --- a/mm/vmscan.c
> >> +++ b/mm/vmscan.c
> >> @@ -1907,6 +1907,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
> >>  	unsigned long nr_taken;
> >>  	struct reclaim_stat stat;
> >>  	int file = is_file_lru(lru);
> >> +	enum vm_event_item item;
> >>  	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
> >>  	struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
> >>  	bool stalled = false;
> >> @@ -1934,17 +1935,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
> >>  	__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken);
> >>  	reclaim_stat->recent_scanned[file] += nr_taken;
> >>  
> >> -	if (current_is_kswapd()) {
> >> -		if (global_reclaim(sc))
> >> -			__count_vm_events(PGSCAN_KSWAPD, nr_scanned);
> >> -		count_memcg_events(lruvec_memcg(lruvec), PGSCAN_KSWAPD,
> >> -				   nr_scanned);
> >> -	} else {
> >> -		if (global_reclaim(sc))
> >> -			__count_vm_events(PGSCAN_DIRECT, nr_scanned);
> >> -		count_memcg_events(lruvec_memcg(lruvec), PGSCAN_DIRECT,
> >> -				   nr_scanned);
> >> -	}
> >> +	item = current_is_kswapd() ? PGSCAN_KSWAPD : PGSCAN_DIRECT;
> >> +	if (global_reclaim(sc))
> >> +		__count_vm_events(item, nr_scanned);
> >> +	__count_memcg_events(lruvec_memcg(lruvec), item, nr_scanned);
> >>  	spin_unlock_irq(&pgdat->lru_lock);
> >>  
> >>  	if (nr_taken == 0)
> >> @@ -1955,17 +1949,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
> >>  
> >>  	spin_lock_irq(&pgdat->lru_lock);
> >>  
> >> -	if (current_is_kswapd()) {
> >> -		if (global_reclaim(sc))
> >> -			__count_vm_events(PGSTEAL_KSWAPD, nr_reclaimed);
> >> -		count_memcg_events(lruvec_memcg(lruvec), PGSTEAL_KSWAPD,
> >> -				   nr_reclaimed);
> >> -	} else {
> >> -		if (global_reclaim(sc))
> >> -			__count_vm_events(PGSTEAL_DIRECT, nr_reclaimed);
> >> -		count_memcg_events(lruvec_memcg(lruvec), PGSTEAL_DIRECT,
> >> -				   nr_reclaimed);
> >> -	}
> >> +	item = current_is_kswapd() ? PGSTEAL_KSWAPD : PGSTEAL_DIRECT;
> >> +	if (global_reclaim(sc))
> >> +		__count_vm_events(item, nr_reclaimed);
> >> +	__count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed);
> >>  	reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
> >>  	reclaim_stat->recent_rotated[1] = stat.nr_activate[1];
> >>  
> > 
> 

-- 
Michal Hocko
SUSE Labs