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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-11-14 15:54:27 +0900
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-11-20 10:05:50 +0900
commitdb38d5ad323362bfca118b52fe5906f97a69fb45 (patch)
tree11940fedf0eb0ff80527094bd435ec89641f8adc /fs/nilfs2
parent141bbdba9c2c1592d56b019277774099a5412aea (diff)
downloadlinux-db38d5ad323362bfca118b52fe5906f97a69fb45.tar.gz
nilfs2: add cache framework for persistent object allocator
This adds setup and cleanup routines of the persistent object allocator cache. According to ftrace analyses, accessing buffers of the DAT file suffers indispensable overhead many times. To mitigate the overhead, This introduce cache framework for the persistent object allocator (palloc) which the DAT file and ifile are using. struct nilfs_palloc_cache represents the cache object per metadata file using palloc. The cache is initialized through nilfs_palloc_setup_cache() and destroyed by nilfs_palloc_destroy_cache(); callers of the former function will be added to individual allocators of DAT and ifile on successive patches. nilfs_palloc_destroy_cache() will be called from nilfs_mdt_destroy() if the cache is attached to a metadata file. A companion function nilfs_palloc_clear_cache() is provided to allow releasing buffer head references independently with the cleanup task. This adjunctive function will be used before invalidating pages of metadata file with the cache. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2')
-rw-r--r--fs/nilfs2/alloc.c27
-rw-r--r--fs/nilfs2/alloc.h21
-rw-r--r--fs/nilfs2/mdt.c2
-rw-r--r--fs/nilfs2/mdt.h2
4 files changed, 52 insertions, 0 deletions
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index 7e2b3ce57aa..c56300d8d17 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -491,3 +491,30 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
}
return 0;
}
+
+void nilfs_palloc_setup_cache(struct inode *inode,
+ struct nilfs_palloc_cache *cache)
+{
+ NILFS_MDT(inode)->mi_palloc_cache = cache;
+ spin_lock_init(&cache->lock);
+}
+
+void nilfs_palloc_clear_cache(struct inode *inode)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ spin_lock(&cache->lock);
+ brelse(cache->prev_desc.bh);
+ brelse(cache->prev_bitmap.bh);
+ brelse(cache->prev_entry.bh);
+ cache->prev_desc.bh = NULL;
+ cache->prev_bitmap.bh = NULL;
+ cache->prev_entry.bh = NULL;
+ spin_unlock(&cache->lock);
+}
+
+void nilfs_palloc_destroy_cache(struct inode *inode)
+{
+ nilfs_palloc_clear_cache(inode);
+ NILFS_MDT(inode)->mi_palloc_cache = NULL;
+}
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index 4ace5475c2c..f4543ac4f56 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -69,4 +69,25 @@ int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
#define nilfs_clear_bit_atomic ext2_clear_bit_atomic
#define nilfs_find_next_zero_bit ext2_find_next_zero_bit
+/*
+ * persistent object allocator cache
+ */
+
+struct nilfs_bh_assoc {
+ unsigned long blkoff;
+ struct buffer_head *bh;
+};
+
+struct nilfs_palloc_cache {
+ spinlock_t lock;
+ struct nilfs_bh_assoc prev_desc;
+ struct nilfs_bh_assoc prev_bitmap;
+ struct nilfs_bh_assoc prev_entry;
+};
+
+void nilfs_palloc_setup_cache(struct inode *inode,
+ struct nilfs_palloc_cache *cache);
+void nilfs_palloc_clear_cache(struct inode *inode);
+void nilfs_palloc_destroy_cache(struct inode *inode);
+
#endif /* _NILFS_ALLOC_H */
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index 948b1f8bc50..06713ffcc7f 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -571,6 +571,8 @@ void nilfs_mdt_destroy(struct inode *inode)
{
struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
+ if (mdi->mi_palloc_cache)
+ nilfs_palloc_destroy_cache(inode);
nilfs_mdt_clear(inode);
kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h
index c396b6c0393..6c4bbb0470f 100644
--- a/fs/nilfs2/mdt.h
+++ b/fs/nilfs2/mdt.h
@@ -36,6 +36,7 @@
* @mi_entry_size: size of an entry
* @mi_first_entry_offset: offset to the first entry
* @mi_entries_per_block: number of entries in a block
+ * @mi_palloc_cache: persistent object allocator cache
* @mi_blocks_per_group: number of blocks in a group
* @mi_blocks_per_desc_block: number of blocks per descriptor block
*/
@@ -46,6 +47,7 @@ struct nilfs_mdt_info {
unsigned mi_entry_size;
unsigned mi_first_entry_offset;
unsigned long mi_entries_per_block;
+ struct nilfs_palloc_cache *mi_palloc_cache;
unsigned long mi_blocks_per_group;
unsigned long mi_blocks_per_desc_block;
};