Hi Ted: On Wed, Apr 29, 2009 at 2:50 PM, Theodore Tso <tytso@xxxxxxx> wrote: > Oh --- one more question. You did these tests on your 2.6.26-based > kernel with ext4 backports, right? Not 2.6.30 mainline kernel? Did > you backport the changes to the block and inode allocators? i.e., > this patch (plus a 1 or 2 subsequent bug fixes)? > > > commit a4912123b688e057084e6557cef8924f7ae5bbde > Author: Theodore Ts'o <tytso@xxxxxxx> > Date: Thu Mar 12 12:18:34 2009 -0400 > > ext4: New inode/block allocation algorithms for flex_bg filesystems Yes, we have this patch. I'm not sure if we have the "1 or 2" bug fixes you refer to above; do you have commits for these? I'm regen'ing the e2fsck and debugfs output for the 3 "dd" sequence above, for our stock kernel and for this + Andreas' patch. Thanks, Curt > > The find_group_flex() inode allocator is now only used if the > filesystem is mounted using the "oldalloc" mount option. It is > replaced with the original Orlov allocator that has been updated for > flex_bg filesystems (it should behave the same way if flex_bg is > disabled). The inode allocator now functions by taking into account > each flex_bg group, instead of each block group, when deciding whether > or not it's time to allocate a new directory into a fresh flex_bg. > > The block allocator has also been changed so that the first block > group in each flex_bg is preferred for use for storing directory > blocks. This keeps directory blocks close together, which is good for > speeding up e2fsck since large directories are more likely to look > like this: > > debugfs: stat /home/tytso/Maildir/cur > Inode: 1844562 Type: directory Mode: 0700 Flags: 0x81000 > Generation: 1132745781 Version: 0x00000000:0000ad71 > User: 15806 Group: 15806 Size: 1060864 > File ACL: 0 Directory ACL: 0 > Links: 2 Blockcount: 2072 > Fragment: Address: 0 Number: 0 Size: 0 > ctime: 0x499c0ff4:164961f4 -- Wed Feb 18 08:41:08 2009 > atime: 0x499c0ff4:00000000 -- Wed Feb 18 08:41:08 2009 > mtime: 0x49957f51:00000000 -- Fri Feb 13 09:10:25 2009 > crtime: 0x499c0f57:00d51440 -- Wed Feb 18 08:38:31 2009 > Size of extra inode fields: 28 > BLOCKS: > (0):7348651, (1-258):7348654-7348911 > TOTAL: 259 > > Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> > > - Ted > -- 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
