TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

jffs2: Dynamically choose inocache hash size

Browse Source 
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>
This commit is contained in:
Daniel Drake
2010-10-07 19:14:02 +01:00
committed by David Woodhouse
parent b46daf7eb1
commit 65e5a0e18e
5 changed files with 29 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/jffs2/fs.c
+21 -1
View File
@@ -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;