summaryrefslogtreecommitdiffstats
path: root/mm/vmscan.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c145
1 files changed, 95 insertions, 50 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d036e59d302..b55699cd906 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -95,8 +95,6 @@ struct scan_control {
/* Can pages be swapped as part of reclaim? */
int may_swap;
- int swappiness;
-
int order;
/*
@@ -173,7 +171,8 @@ static unsigned long zone_nr_lru_pages(struct zone *zone,
struct scan_control *sc, enum lru_list lru)
{
if (!scanning_global_lru(sc))
- return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup, zone, lru);
+ return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup,
+ zone_to_nid(zone), zone_idx(zone), BIT(lru));
return zone_page_state(zone, NR_LRU_BASE + lru);
}
@@ -250,49 +249,90 @@ unsigned long shrink_slab(struct shrink_control *shrink,
unsigned long long delta;
unsigned long total_scan;
unsigned long max_pass;
+ int shrink_ret = 0;
+ long nr;
+ long new_nr;
+ long batch_size = shrinker->batch ? shrinker->batch
+ : SHRINK_BATCH;
+
+ /*
+ * copy the current shrinker scan count into a local variable
+ * and zero it so that other concurrent shrinker invocations
+ * don't also do this scanning work.
+ */
+ do {
+ nr = shrinker->nr;
+ } while (cmpxchg(&shrinker->nr, nr, 0) != nr);
+ total_scan = nr;
max_pass = do_shrinker_shrink(shrinker, shrink, 0);
delta = (4 * nr_pages_scanned) / shrinker->seeks;
delta *= max_pass;
do_div(delta, lru_pages + 1);
- shrinker->nr += delta;
- if (shrinker->nr < 0) {
+ total_scan += delta;
+ if (total_scan < 0) {
printk(KERN_ERR "shrink_slab: %pF negative objects to "
"delete nr=%ld\n",
- shrinker->shrink, shrinker->nr);
- shrinker->nr = max_pass;
+ shrinker->shrink, total_scan);
+ total_scan = max_pass;
}
/*
+ * We need to avoid excessive windup on filesystem shrinkers
+ * due to large numbers of GFP_NOFS allocations causing the
+ * shrinkers to return -1 all the time. This results in a large
+ * nr being built up so when a shrink that can do some work
+ * comes along it empties the entire cache due to nr >>>
+ * max_pass. This is bad for sustaining a working set in
+ * memory.
+ *
+ * Hence only allow the shrinker to scan the entire cache when
+ * a large delta change is calculated directly.
+ */
+ if (delta < max_pass / 4)
+ total_scan = min(total_scan, max_pass / 2);
+
+ /*
* Avoid risking looping forever due to too large nr value:
* never try to free more than twice the estimate number of
* freeable entries.
*/
- if (shrinker->nr > max_pass * 2)
- shrinker->nr = max_pass * 2;
+ if (total_scan > max_pass * 2)
+ total_scan = max_pass * 2;
- total_scan = shrinker->nr;
- shrinker->nr = 0;
+ trace_mm_shrink_slab_start(shrinker, shrink, nr,
+ nr_pages_scanned, lru_pages,
+ max_pass, delta, total_scan);
- while (total_scan >= SHRINK_BATCH) {
- long this_scan = SHRINK_BATCH;
- int shrink_ret;
+ while (total_scan >= batch_size) {
int nr_before;
nr_before = do_shrinker_shrink(shrinker, shrink, 0);
shrink_ret = do_shrinker_shrink(shrinker, shrink,
- this_scan);
+ batch_size);
if (shrink_ret == -1)
break;
if (shrink_ret < nr_before)
ret += nr_before - shrink_ret;
- count_vm_events(SLABS_SCANNED, this_scan);
- total_scan -= this_scan;
+ count_vm_events(SLABS_SCANNED, batch_size);
+ total_scan -= batch_size;
cond_resched();
}
- shrinker->nr += total_scan;
+ /*
+ * move the unused scan count back into the shrinker in a
+ * manner that handles concurrent updates. If we exhausted the
+ * scan, there is no need to do an update.
+ */
+ do {
+ nr = shrinker->nr;
+ new_nr = total_scan + nr;
+ if (total_scan <= 0)
+ break;
+ } while (cmpxchg(&shrinker->nr, nr, new_nr) != nr);
+
+ trace_mm_shrink_slab_end(shrinker, shrink_ret, nr, new_nr);
}
up_read(&shrinker_rwsem);
out:
@@ -1729,6 +1769,13 @@ static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
}
+static int vmscan_swappiness(struct scan_control *sc)
+{
+ if (scanning_global_lru(sc))
+ return vm_swappiness;
+ return mem_cgroup_swappiness(sc->mem_cgroup);
+}
+
/*
* Determine how aggressively the anon and file LRU lists should be
* scanned. The relative value of each set of LRU lists is determined
@@ -1747,22 +1794,15 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
u64 fraction[2], denominator;
enum lru_list l;
int noswap = 0;
- int force_scan = 0;
+ bool force_scan = false;
+ unsigned long nr_force_scan[2];
-
- anon = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
- zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
- file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
- zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
-
- if (((anon + file) >> priority) < SWAP_CLUSTER_MAX) {
- /* kswapd does zone balancing and need to scan this zone */
- if (scanning_global_lru(sc) && current_is_kswapd())
- force_scan = 1;
- /* memcg may have small limit and need to avoid priority drop */
- if (!scanning_global_lru(sc))
- force_scan = 1;
- }
+ /* kswapd does zone balancing and needs to scan this zone */
+ if (scanning_global_lru(sc) && current_is_kswapd())
+ force_scan = true;
+ /* memcg may have small limit and need to avoid priority drop */
+ if (!scanning_global_lru(sc))
+ force_scan = true;
/* If we have no swap space, do not bother scanning anon pages. */
if (!sc->may_swap || (nr_swap_pages <= 0)) {
@@ -1770,9 +1810,16 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
fraction[0] = 0;
fraction[1] = 1;
denominator = 1;
+ nr_force_scan[0] = 0;
+ nr_force_scan[1] = SWAP_CLUSTER_MAX;
goto out;
}
+ anon = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
+ zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
+ file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
+ zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+
if (scanning_global_lru(sc)) {
free = zone_page_state(zone, NR_FREE_PAGES);
/* If we have very few page cache pages,
@@ -1781,6 +1828,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
fraction[0] = 1;
fraction[1] = 0;
denominator = 1;
+ nr_force_scan[0] = SWAP_CLUSTER_MAX;
+ nr_force_scan[1] = 0;
goto out;
}
}
@@ -1789,8 +1838,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
* With swappiness at 100, anonymous and file have the same priority.
* This scanning priority is essentially the inverse of IO cost.
*/
- anon_prio = sc->swappiness;
- file_prio = 200 - sc->swappiness;
+ anon_prio = vmscan_swappiness(sc);
+ file_prio = 200 - vmscan_swappiness(sc);
/*
* OK, so we have swap space and a fair amount of page cache
@@ -1829,6 +1878,11 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
fraction[0] = ap;
fraction[1] = fp;
denominator = ap + fp + 1;
+ if (force_scan) {
+ unsigned long scan = SWAP_CLUSTER_MAX;
+ nr_force_scan[0] = div64_u64(scan * ap, denominator);
+ nr_force_scan[1] = div64_u64(scan * fp, denominator);
+ }
out:
for_each_evictable_lru(l) {
int file = is_file_lru(l);
@@ -1849,12 +1903,8 @@ out:
* memcg, priority drop can cause big latency. So, it's better
* to scan small amount. See may_noscan above.
*/
- if (!scan && force_scan) {
- if (file)
- scan = SWAP_CLUSTER_MAX;
- else if (!noswap)
- scan = SWAP_CLUSTER_MAX;
- }
+ if (!scan && force_scan)
+ scan = nr_force_scan[file];
nr[l] = scan;
}
}
@@ -2179,7 +2229,6 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
.nr_to_reclaim = SWAP_CLUSTER_MAX,
.may_unmap = 1,
.may_swap = 1,
- .swappiness = vm_swappiness,
.order = order,
.mem_cgroup = NULL,
.nodemask = nodemask,
@@ -2203,7 +2252,6 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap,
- unsigned int swappiness,
struct zone *zone,
unsigned long *nr_scanned)
{
@@ -2213,7 +2261,6 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
.may_writepage = !laptop_mode,
.may_unmap = 1,
.may_swap = !noswap,
- .swappiness = swappiness,
.order = 0,
.mem_cgroup = mem,
};
@@ -2242,8 +2289,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
gfp_t gfp_mask,
- bool noswap,
- unsigned int swappiness)
+ bool noswap)
{
struct zonelist *zonelist;
unsigned long nr_reclaimed;
@@ -2253,7 +2299,6 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
.may_unmap = 1,
.may_swap = !noswap,
.nr_to_reclaim = SWAP_CLUSTER_MAX,
- .swappiness = swappiness,
.order = 0,
.mem_cgroup = mem_cont,
.nodemask = NULL, /* we don't care the placement */
@@ -2404,7 +2449,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
* we want to put equal scanning pressure on each zone.
*/
.nr_to_reclaim = ULONG_MAX,
- .swappiness = vm_swappiness,
.order = order,
.mem_cgroup = NULL,
};
@@ -2453,6 +2497,9 @@ loop_again:
high_wmark_pages(zone), 0, 0)) {
end_zone = i;
break;
+ } else {
+ /* If balanced, clear the congested flag */
+ zone_clear_flag(zone, ZONE_CONGESTED);
}
}
if (i < 0)
@@ -2874,7 +2921,6 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
.may_writepage = 1,
.nr_to_reclaim = nr_to_reclaim,
.hibernation_mode = 1,
- .swappiness = vm_swappiness,
.order = 0,
};
struct shrink_control shrink = {
@@ -3061,7 +3107,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
.nr_to_reclaim = max_t(unsigned long, nr_pages,
SWAP_CLUSTER_MAX),
.gfp_mask = gfp_mask,
- .swappiness = vm_swappiness,
.order = order,
};
struct shrink_control shrink = {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-29 17:59:56 +0000