> > This patch consolidates existing parameters to shrink_slab() to
> > a new shrink_control struct. This is needed later to pass the same
> > struct to shrinkers.
> >
> > changelog v2..v1:
> > 1. define a new struct shrink_control and only pass some values down
> > to the shrinker instead of the scan_control.
> >
> > Signed-off-by: Ying Han <yinghan@xxxxxxxxxx>
> > ---
> > fs/drop_caches.c | 6 +++++-
> > include/linux/mm.h | 13 +++++++++++--
> > mm/vmscan.c | 30 ++++++++++++++++++++++--------
> > 3 files changed, 38 insertions(+), 11 deletions(-)
>
> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Sigh. No. This patch seems premature.
> This patch consolidates existing parameters to shrink_slab() to
> a new shrink_control struct. This is needed later to pass the same
> struct to shrinkers.
>
> changelog v2..v1:
> 1. define a new struct shrink_control and only pass some values down
> to the shrinker instead of the scan_control.
>
> Signed-off-by: Ying Han <yinghan@xxxxxxxxxx>
> ---
> fs/drop_caches.c | 6 +++++-
> include/linux/mm.h | 13 +++++++++++--
> mm/vmscan.c | 30 ++++++++++++++++++++++--------
> 3 files changed, 38 insertions(+), 11 deletions(-)
>
> diff --git a/fs/drop_caches.c b/fs/drop_caches.c
> index 816f88e..c671290 100644
> --- a/fs/drop_caches.c
> +++ b/fs/drop_caches.c
> @@ -36,9 +36,13 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
> static void drop_slab(void)
> {
> int nr_objects;
> + struct shrink_control shrink = {
> + .gfp_mask = GFP_KERNEL,
> + .nr_scanned = 1000,
> + };
>
> do {
> - nr_objects = shrink_slab(1000, GFP_KERNEL, 1000);
> + nr_objects = shrink_slab(&shrink, 1000);
> } while (nr_objects > 10);
> }
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 0716517..7a2f657 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1131,6 +1131,15 @@ static inline void sync_mm_rss(struct task_struct *task, struct mm_struct *mm)
> #endif
>
> /*
> + * This struct is used to pass information from page reclaim to the shrinkers.
> + * We consolidate the values for easier extention later.
> + */
> +struct shrink_control {
> + unsigned long nr_scanned;
nr_to_scan is better. sc.nr_scanned mean how much _finished_ scan pages.
eg.
scan_control {
(snip)
/* Number of pages freed so far during a call to shrink_zones() */
unsigned long nr_reclaimed;
/* How many pages shrink_list() should reclaim */
unsigned long nr_to_reclaim;
> + gfp_t gfp_mask;
> +};
> +
> +/*
> * A callback you can register to apply pressure to ageable caches.
> *
> * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'. It should
> @@ -1601,8 +1610,8 @@ int in_gate_area_no_task(unsigned long addr);
>
> int drop_caches_sysctl_handler(struct ctl_table *, int,
> void __user *, size_t *, loff_t *);
> -unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
> - unsigned long lru_pages);
> +unsigned long shrink_slab(struct shrink_control *shrink,
> + unsigned long lru_pages);
>
> #ifndef CONFIG_MMU
> #define randomize_va_space 0
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 060e4c1..40edf73 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -220,11 +220,13 @@ EXPORT_SYMBOL(unregister_shrinker);
> *
> * Returns the number of slab objects which we shrunk.
> */
> -unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
> - unsigned long lru_pages)
> +unsigned long shrink_slab(struct shrink_control *shrink,
> + unsigned long lru_pages)
> {
> struct shrinker *shrinker;
> unsigned long ret = 0;
> + unsigned long scanned = shrink->nr_scanned;
> + gfp_t gfp_mask = shrink->gfp_mask;
>
> if (scanned == 0)
> scanned = SWAP_CLUSTER_MAX;
> @@ -2032,7 +2034,8 @@ static bool all_unreclaimable(struct zonelist *zonelist,
> * else, the number of pages reclaimed
> */
> static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
> - struct scan_control *sc)
> + struct scan_control *sc,
> + struct shrink_control *shrink)
> {
Worthless argument addition. gfpmask can be getting from scan_control and
.nr_scanned is calculated in this function.
> int priority;
> unsigned long total_scanned = 0;
> @@ -2066,7 +2069,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
> lru_pages += zone_reclaimable_pages(zone);
> }
>
> - shrink_slab(sc->nr_scanned, sc->gfp_mask, lru_pages);
> + shrink->nr_scanned = sc->nr_scanned;
> + shrink_slab(shrink, lru_pages);
> if (reclaim_state) {
> sc->nr_reclaimed += reclaim_state->reclaimed_slab;
> reclaim_state->reclaimed_slab = 0;
> @@ -2130,12 +2134,15 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
> .mem_cgroup = NULL,
> .nodemask = nodemask,
> };
> + struct shrink_control shrink = {
> + .gfp_mask = sc.gfp_mask,
> + };
>
> trace_mm_vmscan_direct_reclaim_begin(order,
> sc.may_writepage,
> gfp_mask);
>
> - nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
> + nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
>
> trace_mm_vmscan_direct_reclaim_end(nr_reclaimed);
>
> @@ -2333,6 +2340,9 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
> .order = order,
> .mem_cgroup = NULL,
> };
> + struct shrink_control shrink = {
> + .gfp_mask = sc.gfp_mask,
> + };
> loop_again:
> total_scanned = 0;
> sc.nr_reclaimed = 0;
> @@ -2432,8 +2442,8 @@ loop_again:
> end_zone, 0))
> shrink_zone(priority, zone, &sc);
> reclaim_state->reclaimed_slab = 0;
> - nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,
> - lru_pages);
> + shrink.nr_scanned = sc.nr_scanned;
> + nr_slab = shrink_slab(&shrink, lru_pages);
> sc.nr_reclaimed += reclaim_state->reclaimed_slab;
> total_scanned += sc.nr_scanned;
>
> @@ -2969,6 +2979,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
> .swappiness = vm_swappiness,
> .order = order,
> };
> + struct shrink_control shrink = {
> + .gfp_mask = sc.gfp_mask,
> + };
> unsigned long nr_slab_pages0, nr_slab_pages1;
>
> cond_resched();
> @@ -2995,6 +3008,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
> }
>
> nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
> + shrink.nr_scanned = sc.nr_scanned;
> if (nr_slab_pages0 > zone->min_slab_pages) {
strange. this assignment should be move into this if brace.
> /*
> * shrink_slab() does not currently allow us to determine how
> @@ -3010,7 +3024,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
> unsigned long lru_pages = zone_reclaimable_pages(zone);
>
> /* No reclaimable slab or very low memory pressure */
> - if (!shrink_slab(sc.nr_scanned, gfp_mask, lru_pages))
> + if (!shrink_slab(&shrink, lru_pages))
> break;
>
> /* Freed enough memory */
> --
> 1.7.3.1
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxxx For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href