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Diffstat (limited to 'fs/ext4/extents_status.c')
-rw-r--r--fs/ext4/extents_status.c200
1 files changed, 182 insertions, 18 deletions
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 0b7e28e..94e7855 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -11,6 +11,8 @@
*/
#include <linux/rbtree.h>
#include <linux/list_sort.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
#include "ext4.h"
#include "extents_status.h"
@@ -313,19 +315,27 @@ ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
*/
if (!ext4_es_is_delayed(es)) {
EXT4_I(inode)->i_es_lru_nr++;
- percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_extent_cache_cnt);
+ percpu_counter_inc(&EXT4_SB(inode->i_sb)->
+ s_es_stats.es_stats_lru_cnt);
}
+ EXT4_I(inode)->i_es_all_nr++;
+ percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
+
return es;
}
static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
{
+ EXT4_I(inode)->i_es_all_nr--;
+ percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
+
/* Decrease the lru counter when this es is not delayed */
if (!ext4_es_is_delayed(es)) {
BUG_ON(EXT4_I(inode)->i_es_lru_nr == 0);
EXT4_I(inode)->i_es_lru_nr--;
- percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_extent_cache_cnt);
+ percpu_counter_dec(&EXT4_SB(inode->i_sb)->
+ s_es_stats.es_stats_lru_cnt);
}
kmem_cache_free(ext4_es_cachep, es);
@@ -426,7 +436,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
unsigned short ee_len;
int depth, ee_status, es_status;
- path = ext4_ext_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
+ path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
if (IS_ERR(path))
return;
@@ -499,10 +509,8 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
}
}
out:
- if (path) {
- ext4_ext_drop_refs(path);
- kfree(path);
- }
+ ext4_ext_drop_refs(path);
+ kfree(path);
}
static void ext4_es_insert_extent_ind_check(struct inode *inode,
@@ -731,6 +739,7 @@ int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
struct extent_status *es)
{
struct ext4_es_tree *tree;
+ struct ext4_es_stats *stats;
struct extent_status *es1 = NULL;
struct rb_node *node;
int found = 0;
@@ -767,11 +776,15 @@ int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
}
out:
+ stats = &EXT4_SB(inode->i_sb)->s_es_stats;
if (found) {
BUG_ON(!es1);
es->es_lblk = es1->es_lblk;
es->es_len = es1->es_len;
es->es_pblk = es1->es_pblk;
+ stats->es_stats_cache_hits++;
+ } else {
+ stats->es_stats_cache_misses++;
}
read_unlock(&EXT4_I(inode)->i_es_lock);
@@ -933,11 +946,16 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
struct ext4_inode_info *locked_ei)
{
struct ext4_inode_info *ei;
+ struct ext4_es_stats *es_stats;
struct list_head *cur, *tmp;
LIST_HEAD(skipped);
+ ktime_t start_time;
+ u64 scan_time;
int nr_shrunk = 0;
int retried = 0, skip_precached = 1, nr_skipped = 0;
+ es_stats = &sbi->s_es_stats;
+ start_time = ktime_get();
spin_lock(&sbi->s_es_lru_lock);
retry:
@@ -948,7 +966,8 @@ retry:
* If we have already reclaimed all extents from extent
* status tree, just stop the loop immediately.
*/
- if (percpu_counter_read_positive(&sbi->s_extent_cache_cnt) == 0)
+ if (percpu_counter_read_positive(
+ &es_stats->es_stats_lru_cnt) == 0)
break;
ei = list_entry(cur, struct ext4_inode_info, i_es_lru);
@@ -958,7 +977,7 @@ retry:
* time. Normally we try hard to avoid shrinking
* precached inodes, but we will as a last resort.
*/
- if ((sbi->s_es_last_sorted < ei->i_touch_when) ||
+ if ((es_stats->es_stats_last_sorted < ei->i_touch_when) ||
(skip_precached && ext4_test_inode_state(&ei->vfs_inode,
EXT4_STATE_EXT_PRECACHED))) {
nr_skipped++;
@@ -992,7 +1011,7 @@ retry:
if ((nr_shrunk == 0) && nr_skipped && !retried) {
retried++;
list_sort(NULL, &sbi->s_es_lru, ext4_inode_touch_time_cmp);
- sbi->s_es_last_sorted = jiffies;
+ es_stats->es_stats_last_sorted = jiffies;
ei = list_first_entry(&sbi->s_es_lru, struct ext4_inode_info,
i_es_lru);
/*
@@ -1010,6 +1029,22 @@ retry:
if (locked_ei && nr_shrunk == 0)
nr_shrunk = __es_try_to_reclaim_extents(locked_ei, nr_to_scan);
+ scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
+ if (likely(es_stats->es_stats_scan_time))
+ es_stats->es_stats_scan_time = (scan_time +
+ es_stats->es_stats_scan_time*3) / 4;
+ else
+ es_stats->es_stats_scan_time = scan_time;
+ if (scan_time > es_stats->es_stats_max_scan_time)
+ es_stats->es_stats_max_scan_time = scan_time;
+ if (likely(es_stats->es_stats_shrunk))
+ es_stats->es_stats_shrunk = (nr_shrunk +
+ es_stats->es_stats_shrunk*3) / 4;
+ else
+ es_stats->es_stats_shrunk = nr_shrunk;
+
+ trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time, skip_precached,
+ nr_skipped, retried);
return nr_shrunk;
}
@@ -1020,8 +1055,8 @@ static unsigned long ext4_es_count(struct shrinker *shrink,
struct ext4_sb_info *sbi;
sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker);
- nr = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
- trace_ext4_es_shrink_enter(sbi->s_sb, sc->nr_to_scan, nr);
+ nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_lru_cnt);
+ trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
return nr;
}
@@ -1033,31 +1068,160 @@ static unsigned long ext4_es_scan(struct shrinker *shrink,
int nr_to_scan = sc->nr_to_scan;
int ret, nr_shrunk;
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
- trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
+ ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_lru_cnt);
+ trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
if (!nr_to_scan)
return ret;
nr_shrunk = __ext4_es_shrink(sbi, nr_to_scan, NULL);
- trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret);
+ trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
return nr_shrunk;
}
-void ext4_es_register_shrinker(struct ext4_sb_info *sbi)
+static void *ext4_es_seq_shrinker_info_start(struct seq_file *seq, loff_t *pos)
{
+ return *pos ? NULL : SEQ_START_TOKEN;
+}
+
+static void *
+ext4_es_seq_shrinker_info_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ return NULL;
+}
+
+static int ext4_es_seq_shrinker_info_show(struct seq_file *seq, void *v)
+{
+ struct ext4_sb_info *sbi = seq->private;
+ struct ext4_es_stats *es_stats = &sbi->s_es_stats;
+ struct ext4_inode_info *ei, *max = NULL;
+ unsigned int inode_cnt = 0;
+
+ if (v != SEQ_START_TOKEN)
+ return 0;
+
+ /* here we just find an inode that has the max nr. of objects */
+ spin_lock(&sbi->s_es_lru_lock);
+ list_for_each_entry(ei, &sbi->s_es_lru, i_es_lru) {
+ inode_cnt++;
+ if (max && max->i_es_all_nr < ei->i_es_all_nr)
+ max = ei;
+ else if (!max)
+ max = ei;
+ }
+ spin_unlock(&sbi->s_es_lru_lock);
+
+ seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n",
+ percpu_counter_sum_positive(&es_stats->es_stats_all_cnt),
+ percpu_counter_sum_positive(&es_stats->es_stats_lru_cnt));
+ seq_printf(seq, " %lu/%lu cache hits/misses\n",
+ es_stats->es_stats_cache_hits,
+ es_stats->es_stats_cache_misses);
+ if (es_stats->es_stats_last_sorted != 0)
+ seq_printf(seq, " %u ms last sorted interval\n",
+ jiffies_to_msecs(jiffies -
+ es_stats->es_stats_last_sorted));
+ if (inode_cnt)
+ seq_printf(seq, " %d inodes on lru list\n", inode_cnt);
+
+ seq_printf(seq, "average:\n %llu us scan time\n",
+ div_u64(es_stats->es_stats_scan_time, 1000));
+ seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk);
+ if (inode_cnt)
+ seq_printf(seq,
+ "maximum:\n %lu inode (%u objects, %u reclaimable)\n"
+ " %llu us max scan time\n",
+ max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_lru_nr,
+ div_u64(es_stats->es_stats_max_scan_time, 1000));
+
+ return 0;
+}
+
+static void ext4_es_seq_shrinker_info_stop(struct seq_file *seq, void *v)
+{
+}
+
+static const struct seq_operations ext4_es_seq_shrinker_info_ops = {
+ .start = ext4_es_seq_shrinker_info_start,
+ .next = ext4_es_seq_shrinker_info_next,
+ .stop = ext4_es_seq_shrinker_info_stop,
+ .show = ext4_es_seq_shrinker_info_show,
+};
+
+static int
+ext4_es_seq_shrinker_info_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = seq_open(file, &ext4_es_seq_shrinker_info_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = PDE_DATA(inode);
+ }
+
+ return ret;
+}
+
+static int
+ext4_es_seq_shrinker_info_release(struct inode *inode, struct file *file)
+{
+ return seq_release(inode, file);
+}
+
+static const struct file_operations ext4_es_seq_shrinker_info_fops = {
+ .owner = THIS_MODULE,
+ .open = ext4_es_seq_shrinker_info_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = ext4_es_seq_shrinker_info_release,
+};
+
+int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
+{
+ int err;
+
INIT_LIST_HEAD(&sbi->s_es_lru);
spin_lock_init(&sbi->s_es_lru_lock);
- sbi->s_es_last_sorted = 0;
+ sbi->s_es_stats.es_stats_last_sorted = 0;
+ sbi->s_es_stats.es_stats_shrunk = 0;
+ sbi->s_es_stats.es_stats_cache_hits = 0;
+ sbi->s_es_stats.es_stats_cache_misses = 0;
+ sbi->s_es_stats.es_stats_scan_time = 0;
+ sbi->s_es_stats.es_stats_max_scan_time = 0;
+ err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL);
+ if (err)
+ return err;
+ err = percpu_counter_init(&sbi->s_es_stats.es_stats_lru_cnt, 0, GFP_KERNEL);
+ if (err)
+ goto err1;
+
sbi->s_es_shrinker.scan_objects = ext4_es_scan;
sbi->s_es_shrinker.count_objects = ext4_es_count;
sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
- register_shrinker(&sbi->s_es_shrinker);
+ err = register_shrinker(&sbi->s_es_shrinker);
+ if (err)
+ goto err2;
+
+ if (sbi->s_proc)
+ proc_create_data("es_shrinker_info", S_IRUGO, sbi->s_proc,
+ &ext4_es_seq_shrinker_info_fops, sbi);
+
+ return 0;
+
+err2:
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_lru_cnt);
+err1:
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
+ return err;
}
void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
{
+ if (sbi->s_proc)
+ remove_proc_entry("es_shrinker_info", sbi->s_proc);
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_lru_cnt);
unregister_shrinker(&sbi->s_es_shrinker);
}
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