From: Thavatchai Makphaibulchoke Subject: Re: [PATCH v3 0/2] ext4: increase mbcache scalability Date: Thu, 05 Sep 2013 09:49:09 +0000 Message-ID: <52285395.1070508@hp.com> References: <1374108934-50550-1-git-send-email-tmac@hp.com> <1378312756-68597-1-git-send-email-tmac@hp.com> <20130905023522.GA21268@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: Theodore Ts'o , T Makphaibulchoke , adilger.kernel@dilger.ca, viro@zeniv.linux.org.uk, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, aswin@hp.com, torvalds@linux-foundation.org, aswin_proj@groups.hp.com Return-path: In-Reply-To: <20130905023522.GA21268@thunk.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 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.