On 2013-09-25, at 12:43 PM, Thavatchai Makphaibulchoke wrote: > On 09/21/2013 05:12 PM, Andreas Dilger wrote: >> I just noticed that we have a patch for Lustre that adds a "no_mbcache" mount option to disable mbcache on a per-filesystem basis. >> >> The newest patch we have is based on FC19 (3.10 kernel), is this something that would be of interest if we submitted it upstream? >> >> http://review.whamcloud.com/#/c/7263/8/ldiskfs/kernel_patches/patches/fc19/ext4-disable-mb-cache.patch >> >> Cheers, Andreas >> > > Here are some of the improvement I saw with SELinux disabled. To confirm, is this data on your "128-byte inode on ramdisk" config, or is this on a system with a real disk and 256-byte inodes? > On an 80 core machine, > > custom 15.5% > disk 27.81 > fserver 5.33% > new_dbase 9.06% > new_fserver 5.45% > > > On an 8 core machine, > > alltests 5.24 > custom 2.26 > shared 9.32 > short 24.08 > > The rest is not noticably different. This is a pretty significant price to pay for SELinux in any case. I guess it is probably lower overhead with 256-byte inodes, but anything that adds 5-25% overhead shouldn't be taken for granted. Cheers, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
