On Sat, 28 Apr 2007 10:43:28 +0100 Alan Cox <[EMAIL PROTECTED]> wrote:
> On Fri, 27 Apr 2007 21:56:34 -0700 > Andrew Morton <[EMAIL PROTECTED]> wrote: > > > On Sat, 28 Apr 2007 13:17:40 +1000 David Chinner <[EMAIL PROTECTED]> wrote: > > > > > > Fix up your lameo HBA for reads. > > > > > > Where did that come from? You spend 20 lines described the inefficiencies > > > of the readahead in the page cache and it should be fixed but then you > > > turn around and say fix the HBA? > > > > My (repeated) point is that if we populate pagecache with > > physically-contiguous 4k > > pages in this manner then bio+block will be able to create much larger SG > > lists. > > Also remember that even if you do larger pages by using virtual pairs or > quads of real pages because it helps on some systems you end up needing > the same sized sglist as before so you don't make anything worse for > half-assed controllers as you get the same I/O size providing they have > the minimal 2 or 4 sg list entries (and those that don't are genuinely > beyond saving and nowdays very rare) > Could you expand on that a bit please? I don't get it. - 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/
