Re: [PATCH v3 0/2] ext4: increase mbcache scalability

[Thavatchai Makphaibulchoke <thavatchai.makpahibulchoke@hp.com>]

On 09/12/2013 06:23 AM, Theodore Ts'o wrote:
> (I've trimmed the cc list to stop spamming people who probably don't
> care as much about this).
> 
> So I've tried the following patch, and I've confirmed that for short
> xattrs (i.e., that fit inside the inode body, assuming an inode size >
> 128 bytes), the mbcache paths don't trigger at all.
> 
> Could you try this patch and see if we can figure out why mbcache code
> paths are triggering for you?
> 
> 						- Ted
> 

I tried the patch.  First off, looks like the patch has a lot of warnings, it does produces tremendous non-stop warnings during aim7 run, particularly the one from line 1627.

Unfortunately, looks like with this patch we are still calling ext4_xattr_cache_find().

I added more debugging code to print out the first few xattrs that get us into ex4_xattr_cache_find().  This is what I have,

[   80.540977] ext4_xattr_block_set: name  len 28.
[  155.480692] ext4_xattr_block_set: name selinux len 32.
[  155.486531] ext4_xattr_block_set: name selinux len 32.
[  155.492283] ext4_xattr_block_set: name selinux len 32.
[  155.497988] ext4_xattr_block_set: name selinux len 32.
[  155.504064] ext4_xattr_block_set: name selinux len 32.
[  155.509771] ext4_xattr_block_set: name selinux len 32.
[  155.515475] ext4_xattr_block_set: name selinux len 32.
[  155.521179] ext4_xattr_block_set: name selinux len 32.

I'll continue debugging and get back with any new finding.

Thanks,
Mak.