diff options
Diffstat (limited to 'mm/shrinker.c')
| -rw-r--r-- | mm/shrinker.c | 107 |
1 files changed, 106 insertions, 1 deletions
diff --git a/mm/shrinker.c b/mm/shrinker.c index 4a93fd433689..4a76364d2b7e 100644 --- a/mm/shrinker.c +++ b/mm/shrinker.c @@ -1,8 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/memcontrol.h> +#include <linux/rculist.h> #include <linux/rwsem.h> +#include <linux/seq_buf.h> #include <linux/shrinker.h> -#include <linux/rculist.h> #include <trace/events/vmscan.h> #include "internal.h" @@ -411,6 +412,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, trace_mm_shrink_slab_start(shrinker, shrinkctl, nr, freeable, delta, total_scan, priority); + u64 start_time = ktime_get_ns(); /* * Normally, we should not scan less than batch_size objects in one @@ -461,6 +463,17 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, */ new_nr = add_nr_deferred(next_deferred, shrinker, shrinkctl); + unsigned long now = jiffies; + if (freed) { + atomic_long_add(freed, &shrinker->objects_freed); + shrinker->last_freed = now; + } + shrinker->last_scanned = now; + atomic_long_add(scanned, &shrinker->objects_requested_to_free); + + atomic64_add(ktime_get_ns() - start_time, &shrinker->ns_run); + + trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan); return freed; } @@ -809,3 +822,95 @@ void shrinker_free(struct shrinker *shrinker) call_rcu(&shrinker->rcu, shrinker_free_rcu_cb); } EXPORT_SYMBOL_GPL(shrinker_free); + +void shrinker_to_text(struct seq_buf *out, struct shrinker *shrinker) +{ + struct shrink_control sc = { + .gfp_mask = GFP_KERNEL, +#ifdef CONFIG_MEMCG + .memcg = root_mem_cgroup, +#endif + }; + unsigned long nr_freed = atomic_long_read(&shrinker->objects_freed); + + seq_buf_printf(out, "%ps", shrinker->scan_objects); + if (shrinker->name) + seq_buf_printf(out, ": %s", shrinker->name); + seq_buf_putc(out, '\n'); + + seq_buf_printf(out, "objects: %lu\n", shrinker->count_objects(shrinker, &sc)); + seq_buf_printf(out, "requested to free: %lu\n", atomic_long_read(&shrinker->objects_requested_to_free)); + seq_buf_printf(out, "objects freed: %lu\n", nr_freed); + seq_buf_printf(out, "last scanned: %li sec ago\n", (jiffies - shrinker->last_scanned) / HZ); + seq_buf_printf(out, "last freed: %li sec ago\n", (jiffies - shrinker->last_freed) / HZ); + seq_buf_printf(out, "ns per object freed: %llu\n", nr_freed + ? div64_ul(atomic64_read(&shrinker->ns_run), nr_freed) + : 0); + + if (shrinker->to_text) { + shrinker->to_text(out, shrinker); + seq_buf_puts(out, "\n"); + } +} + +/** + * shrinkers_to_text - Report on shrinkers with highest usage + * + * This reports on the top 10 shrinkers, by object counts, in sorted order: + * intended to be used for OOM reporting. + */ +void shrinkers_to_text(struct seq_buf *out) +{ + struct shrinker *shrinker; + struct shrinker_by_mem { + struct shrinker *shrinker; + unsigned long mem; + } shrinkers_by_mem[4]; + int i, nr = 0; + + if (!mutex_trylock(&shrinker_mutex)) { + seq_buf_puts(out, "(couldn't take shrinker lock)"); + return; + } + + list_for_each_entry(shrinker, &shrinker_list, list) { + struct shrink_control sc = { + .gfp_mask = GFP_KERNEL, +#ifdef CONFIG_MEMCG + .memcg = root_mem_cgroup, +#endif + }; + unsigned long mem = shrinker->count_objects(shrinker, &sc); + + if (!mem || mem == SHRINK_STOP || mem == SHRINK_EMPTY) + continue; + + for (i = 0; i < nr; i++) + if (mem < shrinkers_by_mem[i].mem) + break; + + if (nr < ARRAY_SIZE(shrinkers_by_mem)) { + memmove(&shrinkers_by_mem[i + 1], + &shrinkers_by_mem[i], + sizeof(shrinkers_by_mem[0]) * (nr - i)); + nr++; + } else if (i) { + i--; + memmove(&shrinkers_by_mem[0], + &shrinkers_by_mem[1], + sizeof(shrinkers_by_mem[0]) * i); + } else { + continue; + } + + shrinkers_by_mem[i] = (struct shrinker_by_mem) { + .shrinker = shrinker, + .mem = mem, + }; + } + + for (i = nr - 1; i >= 0; --i) + shrinker_to_text(out, shrinkers_by_mem[i].shrinker); + + mutex_unlock(&shrinker_mutex); +} |