diff options
| author | Daniel Drake <dsd@laptop.org> | 2010-10-07 19:14:02 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2010-10-25 00:57:19 +0100 |
| commit | 65e5a0e18e5fb5bc6cfabd8ef4b9fc1c8569ba62 (patch) | |
| tree | 0790ae9e682c5de24b0ffd7111a0bfab4f03aab3 /fs/jffs2/fs.c | |
| parent | b46daf7eb1a143169699a8f9df634aa751a6ddde (diff) | |
jffs2: Dynamically choose inocache hash size
When JFFS2 is used for large volumes, the mount times are quite long.
Increasing the hash size provides a significant speed boost on the OLPC
XO-1 laptop.
Add logic that dynamically selects a hash size based on the size of
the medium. A 64mb medium will result in a hash size of 128, and a 512mb
medium will result in a hash size of 1024.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'fs/jffs2/fs.c')
| -rw-r--r-- | fs/jffs2/fs.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 6b2964a19850..2701b372da78 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -478,6 +478,25 @@ struct inode *jffs2_new_inode (struct inode *dir_i, int mode, struct jffs2_raw_i return inode; } +static int calculate_inocache_hashsize(uint32_t flash_size) +{ + /* + * Pick a inocache hash size based on the size of the medium. + * Count how many megabytes we're dealing with, apply a hashsize twice + * that size, but rounding down to the usual big powers of 2. And keep + * to sensible bounds. + */ + + int size_mb = flash_size / 1024 / 1024; + int hashsize = (size_mb * 2) & ~0x3f; + + if (hashsize < INOCACHE_HASHSIZE_MIN) + return INOCACHE_HASHSIZE_MIN; + if (hashsize > INOCACHE_HASHSIZE_MAX) + return INOCACHE_HASHSIZE_MAX; + + return hashsize; +} int jffs2_do_fill_super(struct super_block *sb, void *data, int silent) { @@ -524,7 +543,8 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent) if (ret) return ret; - c->inocache_list = kcalloc(INOCACHE_HASHSIZE, sizeof(struct jffs2_inode_cache *), GFP_KERNEL); + c->inocache_hashsize = calculate_inocache_hashsize(c->flash_size); + c->inocache_list = kcalloc(c->inocache_hashsize, sizeof(struct jffs2_inode_cache *), GFP_KERNEL); if (!c->inocache_list) { ret = -ENOMEM; goto out_wbuf; |