Re: [PATCH 17/19, v2] mm/migrate: Introduce migrate_misplaced_page()

From: Rik van Riel
Date: Mon Nov 19 2012 - 11:03:08 EST


On 11/18/2012 09:25 PM, Ingo Molnar wrote:

* Ingo Molnar <mingo@xxxxxxxxxx> wrote:

From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>

Add migrate_misplaced_page() which deals with migrating pages from
faults.

This includes adding a new MIGRATE_FAULT migration mode to
deal with the extra page reference required due to having to look up
the page.
[...]

--- a/include/linux/migrate_mode.h
+++ b/include/linux/migrate_mode.h
@@ -6,11 +6,14 @@
* on most operations but not ->writepage as the potential stall time
* is too significant
* MIGRATE_SYNC will block when migrating pages
+ * MIGRATE_FAULT called from the fault path to migrate-on-fault for mempolicy
+ * this path has an extra reference count
*/

Note, this is still the older, open-coded version.

The newer replacement version created from Mel's patch which
reuses migrate_pages() and is nicer on out-of-node-memory
conditions and is cleaner all around can be found below.

I tested it today and it appears to work fine. I noticed no
performance improvement or performance drop from it - if it
holds up in testing it will be part of the -v17 release of
numa/core.

Excellent. That gets rid of the last issue with numa/base :)


--
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/