On Fri, Jul 29, 2011 at 03:48:45AM -0600, Andreas Dilger wrote: > On 2011-07-28, at 4:07 PM, Joel Becker wrote: > > We use ethernet crc32 in ocfs2. btrfs uses crc32c. Frankly, I > > could have used crc32c if I'd really thought about the hardware > > acceleration benefits. I think it's a good idea for ext4. > > The problem with crc32[c] is that if you don't have hardware acceleration > it is terribly slow. We find ethernet crc32 just fine in ocfs2. I use the kernel's implementation, which survives everyone's network traffic, and of course we added the triggers to jbd2 so we only have to do the calculations on read and write. > Yes, it makes sense to just put a "fake" dirent at the end of the leaf block, > or similar. I don't think it is necessary to modify existing directories or > extent blocks to add these structures in, if there is no room, but for new > blocks, or blocks with space it is enough. We have tunefs.ocfs2 code to adjust existing directories to add the trailer. It's not too bad, really. Joel -- "People with narrow minds usually have broad tongues." http://www.jlbec.org/ jlbec@xxxxxxxxxxxx -- 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
