[PATCH 1/2] f2fs: use atomic variable for total_extent_tree

From: Jaegeuk Kim
Date: Mon Dec 21 2015 - 22:38:52 EST


It would be better to use atomic variable for total_extent_tree.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/debug.c | 5 +++--
fs/f2fs/extent_cache.c | 8 ++++----
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/node.c | 3 ++-
fs/f2fs/shrinker.c | 3 ++-
5 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index bb307e6..ed5dfcc 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -38,7 +38,7 @@ static void update_general_status(struct f2fs_sb_info *sbi)
si->hit_rbtree = atomic64_read(&sbi->read_hit_rbtree);
si->hit_total = si->hit_largest + si->hit_cached + si->hit_rbtree;
si->total_ext = atomic64_read(&sbi->total_hit_ext);
- si->ext_tree = sbi->total_ext_tree;
+ si->ext_tree = atomic_read(&sbi->total_ext_tree);
si->ext_node = atomic_read(&sbi->total_ext_node);
si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
@@ -193,7 +193,8 @@ get_cache:
si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages);
for (i = 0; i <= UPDATE_INO; i++)
si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
- si->cache_mem += sbi->total_ext_tree * sizeof(struct extent_tree);
+ si->cache_mem += atomic_read(&sbi->total_ext_tree) *
+ sizeof(struct extent_tree);
si->cache_mem += atomic_read(&sbi->total_ext_node) *
sizeof(struct extent_node);

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index e86e9f1e..0e97d6af 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -70,7 +70,7 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode)
rwlock_init(&et->lock);
atomic_set(&et->refcount, 0);
et->count = 0;
- sbi->total_ext_tree++;
+ atomic_inc(&sbi->total_ext_tree);
}
atomic_inc(&et->refcount);
up_write(&sbi->extent_tree_lock);
@@ -570,7 +570,7 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)

radix_tree_delete(root, et->ino);
kmem_cache_free(extent_tree_slab, et);
- sbi->total_ext_tree--;
+ atomic_dec(&sbi->total_ext_tree);
tree_cnt++;

if (node_cnt + tree_cnt >= nr_shrink)
@@ -663,7 +663,7 @@ void f2fs_destroy_extent_tree(struct inode *inode)
f2fs_bug_on(sbi, atomic_read(&et->refcount) || et->count);
radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
kmem_cache_free(extent_tree_slab, et);
- sbi->total_ext_tree--;
+ atomic_dec(&sbi->total_ext_tree);
up_write(&sbi->extent_tree_lock);

F2FS_I(inode)->extent_tree = NULL;
@@ -715,7 +715,7 @@ void init_extent_cache_info(struct f2fs_sb_info *sbi)
init_rwsem(&sbi->extent_tree_lock);
INIT_LIST_HEAD(&sbi->extent_list);
spin_lock_init(&sbi->extent_lock);
- sbi->total_ext_tree = 0;
+ atomic_set(&sbi->total_ext_tree, 0);
atomic_set(&sbi->total_ext_node, 0);
}

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 19beabe..a7f6191 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -762,7 +762,7 @@ struct f2fs_sb_info {
struct rw_semaphore extent_tree_lock; /* locking extent radix tree */
struct list_head extent_list; /* lru list for shrinker */
spinlock_t extent_lock; /* locking extent lru list */
- int total_ext_tree; /* extent tree count */
+ atomic_t total_ext_tree; /* extent tree count */
atomic_t total_ext_node; /* extent info count */

/* basic filesystem units */
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index d842b19..6cc8ac7 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -65,7 +65,8 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
sizeof(struct ino_entry)) >> PAGE_CACHE_SHIFT;
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
} else if (type == EXTENT_CACHE) {
- mem_size = (sbi->total_ext_tree * sizeof(struct extent_tree) +
+ mem_size = (atomic_read(&sbi->total_ext_tree) *
+ sizeof(struct extent_tree) +
atomic_read(&sbi->total_ext_node) *
sizeof(struct extent_node)) >> PAGE_CACHE_SHIFT;
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index da0d8e0..a11e099 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -32,7 +32,8 @@ static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)

static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
{
- return sbi->total_ext_tree + atomic_read(&sbi->total_ext_node);
+ return atomic_read(&sbi->total_ext_tree) +
+ atomic_read(&sbi->total_ext_node);
}

unsigned long f2fs_shrink_count(struct shrinker *shrink,
--
2.5.4 (Apple Git-61)

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