On Thu, 2007-03-15 at 23:59 +0100, Andrea Arcangeli wrote: > On Thu, Mar 15, 2007 at 05:44:01PM +0000, Hugh Dickins wrote: > > who removed the !offset condition, he should be consulted on its > > reintroduction. > > the !offset check looks a pretty broken heuristic indeed, it would > break random I/O.
I wouldn't call it broken. At worst, I'd say it's imperfect. But that's the nature of a heuristic. It most likely works in a huge majority of cases. > The real fix is to add a ra.prev_offset along with > ra.prev_page, and if who implements it wants to be stylish he can as > well use a ra.last_contiguous_read structure that has a page and > offset fields (and then of course remove ra.prev_page). I suggested something along these lines, but I wonder if it's overkill. The !offset check is simple and appears to be a decent improvement over the current code. -- David Kleikamp IBM Linux Technology Center - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
