Re: [PATCH 04/12] Export fragmentation index via /proc/pagetypeinfo

From: Rik van Riel
Date: Tue Feb 16 2010 - 20:46:13 EST


On 02/12/2010 07:00 AM, Mel Gorman wrote:
Fragmentation index is a value that makes sense when an allocation of a
given size would fail. The index indicates whether an allocation failure is
due to a lack of memory (values towards 0) or due to external fragmentation
(value towards 1). For the most part, the huge page size will be the size
of interest but not necessarily so it is exported on a per-order and per-zone
basis via /proc/pagetypeinfo.

The index is normally calculated as a value between 0 and 1 which is
obviously unsuitable within the kernel. Instead, the first three decimal
places are used as a value between 0 and 1000 for an integer approximation.

Signed-off-by: Mel Gorman<mel@xxxxxxxxx>

Acked-by: Rik van Riel <riel@xxxxxxxxxx>

--
All rights reversed.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/