On Tue, Jan 31, 2017 at 05:41:35AM -0800, Christoph Hellwig wrote: > Hi Darrick, > > from a quick look the code looks reasonable, but I'm worried about > yet another set of transactions that modify all extents again. > > Do you have any measurements of the overhead? I'll see if I > can prototype my always COW idea to see how the approaches compare. The overhead should be pretty low -- since the cow fork never goes to disk, the only thing we end up logging is the inode core (because the conversion function logs it unconditionally), and I'm not even sure that's necessary since we're performing a pure conversion of blocks that are already allocated. In any case I didn't see any noticeable impact on performance other than the extra CPU overhead. --D > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" 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-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
