Re: Avoiding external fragmentation with a placement policy Version 12

David S. Miller
2005-06-03T05:51:28Z

From: "Martin J. Bligh" <mbligh@mbligh.org>
Date: Thu, 02 Jun 2005 22:42:52 -0700

> but it's vastly different order of magnitude than touching disk.
> Can we not do a "sniff alloc" first (ie if this is easy, give it
> to me, else just fail and return w/o reclaim), then fall back to
> smaller allocs?

That's what AF_UNIX does.

But with other protocols, we can't jiggle the loopback
MTU just because higher allocs no longer are easily
obtainable.

Really, the networking should not try to grab anything
more than SKB_MAX_ORDER unless the device's MTU is
larger than PAGE_SIZE << SKB_MAX_ORDER, which loopback's
"16K - fudge" is not.