On Thu, Jan 23, 2014 at 07:55:50AM -0500, Theodore Ts'o wrote: > On Thu, Jan 23, 2014 at 07:35:58PM +1100, Dave Chinner wrote: > > > > > > I expect it would be relatively simple to get large blocksizes working > > > on powerpc with 64k PAGE_SIZE. So before diving in and doing huge > > > amounts of work, perhaps someone can do a proof-of-concept on powerpc > > > (or ia64) with 64k blocksize. > > > > Reality check: 64k block sizes on 64k page Linux machines has been > > used in production on XFS for at least 10 years. It's exactly the > > same case as 4k block size on 4k page size - one page, one buffer > > head, one filesystem block. > > This is true for ext4 as well. Block size == page size support is > pretty easy; the hard part is when block size > page size, due to > assumptions in the VM layer that requires that FS system needs to do a > lot of extra work to fudge around. So the real problem comes with > trying to support 64k block sizes on a 4k page architecture, and can > we do it in a way where every single file system doesn't have to do > their own specific hacks to work around assumptions made in the VM > layer. Yup, ditto for ocfs2. Joel -- "One of the symptoms of an approaching nervous breakdown is the belief that one's work is terribly important." - Bertrand Russell http://www.jlbec.org/ jlbec@xxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html