On Mon, 2012-07-23 at 14:38 +0100, Mel Gorman wrote:

Changelog since V1
  o Expand some of the notes					(jrnieder)
  o Correct upstream commit SHA1				(hugh)

This series is related to the new addition to stable_kernel_rules.txt

 - Serious issues as reported by a user of a distribution kernel may also
   be considered if they fix a notable performance or interactivity issue.
   As these fixes are not as obvious and have a higher risk of a subtle
   regression they should only be submitted by a distribution kernel
   maintainer and include an addendum linking to a bugzilla entry if it
   exists and additional information on the user-visible impact.

All of these patches have been backported to a distribution kernel and
address some sort of performance issue in the VM. As they are not all
obvious, I've added a "Stable note" to the top of each patch giving
additional information on why the patch was backported. Lets see where
the boundaries lie on how this new rule is interpreted in practice :).

Patch 1	Performance fix for tmpfs
Patch 2 Memory hotadd fix
Patch 3 Reduce boot time on large machines
Patches 4-5 Reduce stalls for wait_iff_congested
Patches 6-8 Reduce excessive reclaim of slab objects which for some workloads
	will reduce the amount of IO required
Patches 9-10 limits the amount of page reclaim when THP/Compaction is active.
	Excessive reclaim in low memory situations can lead to stalls some
	of which are user visible.
Patches 11-19 reduce the amount of churn of the LRU lists. Poor reclaim
	decisions can impair workloads in different ways and there have
	been complaints recently the reclaim decisions of modern kernels
	are worse than older ones.
Patches 20-21 reduce the amount of CPU kswapd uses in some cases. This
	is harder to trigger but were developed due to bug reports about
	100% CPU usage from kswapd.
Patches 22-25 are mostly related to interactivity when THP is enabled.
Patches 26-30 are also related to page reclaim decisions, particularly
	the residency of mapped pages.
Patches 31-34 fix a major page allocator performance regression

[...]

The patches are based on 3.0.36 but there should not be problems applying
the series to later stable releases.

[...]

Patches 1-2, 4-15, 20-21, 31-32 correspond to commits included in Linux
3.2.  I've added the rest to the queue for 3.2.y, generally using the
versions Greg has queued for 3.0.39.

Patch 30 'mm: vmscan: convert global reclaim to per-memcg LRU lists'
needed a further context change.

For patch 33 'cpuset: mm: reduce large amounts of memory barrier related
damage v3' I folded in the two fixes Herton pointed out and you
acknowledged, and took the upstream version of the changes to
get_any_partial() in slub.c.

Ben.

-- 
Ben Hutchings
It is impossible to make anything foolproof because fools are so ingenious.