On Friday 13 March 2009 00:59:40 Matthew Wilcox wrote: > On Fri, Mar 13, 2009 at 12:04:40AM +1100, Nick Piggin wrote: > > As far as the per-block pagecache state (as opposed to the per-block fs > > state), I don't see any reason it is a problem for efficiency. We have to > > do per-page operations anyway. > > Why? Wouldn't it be nice if we could do arbitrary extents? I suppose > superpages or soft page sizes get us most of the way there, but the > rounding or pieces at the end are a bit of a pain. Sure, it'll be a > huge upheaval for the VM, but we're good at huge upheavals ;-) Sounds nice in theory. I personally think it would be very very hard to do well, and wouldn't and up being much of a win if at all anyway. But if you have some structure representing arbitrary pagecache extents, then you would probably be able to naturally use those pagecache extents themselves, or parallel very similar data structures for holding block state. -- 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
