On 12/8/10 3:44 PM, Andreas Dilger wrote: > On 2010-12-08, at 14:07, Eric Sandeen wrote: >> On 12/08/2010 01:01 PM, Andreas Dilger wrote: >>> I think an important factor here is that this is being tested on >>> a ramdisk, and is likely CPU bound, so any CPU reduction will >>> directly be measured as a performance improvement. Probably >>> oprofile is in order to see where other major CPU users are. >> >> Yep, I ran oprofile. >> >> samples % app name symbol name 1140046 >> 41.8702 ext2.ko ext2_find_entry 1052117 38.6408 >> ext2.ko ext2_add_link 98424 3.6148 vmlinux >> native_safe_halt 40461 1.4860 vmlinux >> wait_on_page_read 29084 1.0682 vmlinux >> find_get_page >> >> pretty slammed on those 2 ext2 functions! I think it's pretty >> overwhelmed by the linear search. > > Can you test ext4 with nojournal mode, but with dir_index enabled? I > suspect that testing ext2 for directory performance is pointless. Oh, I agree. I just had a report of a regression in a certain distro, which is frowned upon... :) I'm positive ext4 nojournal would beat the pants off it due to dir_index. > My personal threshold for ext2 directories was 10k files before I > considered it a lost cause, and all of your tests are with 10k+ files > per directory. Agreed, it's not very realistic but then it was a simple fix too. Still took time though... > Just another log on the fire beneath getting rid of ext2 (and > eventually ext3) in favour of ext4, IMHO. I'd be surprised if there > are many benchmarks that ext2 can beat ext4 in nojournal mode, if > allowed to enable "reversible" format changes like dir_index, > uninit_bg, etc. Hey, I wouldn't complain. -Eric > 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 -- 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
