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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 05 Sep 2013 09:49:09 +0000
From:	Thavatchai Makphaibulchoke <thavatchai.makpahibulchoke@...com>
To:	Theodore Ts'o <tytso@....edu>, T Makphaibulchoke <tmac@...com>,
	adilger.kernel@...ger.ca, viro@...iv.linux.org.uk,
	linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, aswin@...com,
	torvalds@...ux-foundation.org, aswin_proj@...ups.hp.com
Subject: Re: [PATCH v3 0/2] ext4: increase mbcache scalability

On 09/05/2013 02:35 AM, Theodore Ts'o wrote:
> How did you gather these results?  The mbcache is only used if you are
> using extended attributes, and only if the extended attributes don't
> fit in the inode's extra space.
> 
> I checked aim7, and it doesn't do any extended attribute operations.
> So why are you seeing differences?  Are you doing something like
> deliberately using 128 byte inodes (which is not the default inode
> size), and then enabling SELinux, or some such?
> 
> 						- Ted
> 

No, I did not do anything special, including changing an inode's size. I just used the profile data, which indicated mb_cache module as one of the bottleneck.  Please see below for perf data from one of th new_fserver run, which also shows some mb_cache activities.


                        |--3.51%-- __mb_cache_entry_find
                        |          mb_cache_entry_find_first
                        |          ext4_xattr_cache_find
                        |          ext4_xattr_block_set
                        |          ext4_xattr_set_handle
                        |          ext4_initxattrs
                        |          security_inode_init_security
                        |          ext4_init_security
                        |          __ext4_new_inode
                        |          ext4_create
                        |          vfs_create
                        |          lookup_open
                        |          do_last
                        |          path_openat
                        |          do_filp_open
                        |          do_sys_open
                        |          SyS_open
                        |          sys_creat
                        |          system_call
                        |          __creat_nocancel
                        |          |
                        |          |--16.67%-- 0x11fe2c0
                        |          |

Thanks,
Mak.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/