Re: large page patch

From: David S. Miller (davem@redhat.com)
Date: Thu Aug 01 2002 - 20:19:44 EST


   From: Andrew Morton <akpm@zip.com.au>
   Date: Thu, 01 Aug 2002 18:26:40 -0700

   "David S. Miller" wrote:
> This is probably done to increase the likelyhood that 4MB page orders
> are available. If we collapse 4MB pages deeper, they are less likely
> to be broken up because smaller orders would be selected first.
   
   This is leakage from ia64, which supports up to 256k pages.

Ummm, 4MB > 256K and even with a 4K PAGE_SIZE MAX_ORDER coalesces
up to 4MB already :-)
   
   Apparently a page-table based representation could not be used by PPC.
   
The page-table is just an abstraction, there is no reason dummy
"large" ptes could not be used which are just ignored by the HW TLB
reload code.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:17 EST