Merge tag 'bcm5301x-dt-2014-12-04' of https://github.com/hauke/linux into next/dt
[cascardo/linux.git] / fs / ext4 / extents_status.c
index 0b7e28e..94e7855 100644 (file)
@@ -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);
 }