On Fri, 16 Nov 2012 11:51:24 -0800, Andrew Morton said:

On Fri, 16 Nov 2012 14:14:47 -0500
Josh Boyer [off-list ref] wrote:

quoted

quoted

The temptation is to supply a patch that checks if kswapd was woken for
THP and if so ignore pgdat->kswapd_max_order but it'll be a hack and not
backed up by proper testing. As 3.7 is very close to release and this is
not a bug we should release with, a safer path is to revert "mm: remove
__GFP_NO_KSWAPD" for now and revisit it with the view to ironing out the
balance_pgdat() logic in general.

Signed-off-by: Mel Gorman <mgorman@suse.de>

Does anyone know if this is queued to go into 3.7 somewhere?  I looked
a bit and can't find it in a tree.  We have a few reports of Fedora
rawhide users hitting this.

Still thinking about it.  We're reverting quite a lot of material
lately.
mm-revert-mm-vmscan-scale-number-of-pages-reclaimed-by-reclaim-compaction-based-on-failures.patch
and revert-mm-fix-up-zone-present-pages.patch are queued for 3.7.

I'll toss this one in there as well, but I can't say I'm feeling
terribly confident.  How is Valdis's machine nowadays?

I admit possibly having lost the plot.  With the two patches you mention stuck
on top of next-20121114, I'm seeing less kswapd issues but am still tripping
over them on occasion.  It seems to be related to uptime - I don't see any for
a few hours, but they become more frequent.  I was seeing quite a few of them
yesterday after I had a 30-hour uptime.

I'll stick Mel's "mm: remove __GFP_NO_KSWAPD" patch on this evening and let you
know what happens (might be a day or two before I have definitive results, as
usualally my laptop gets rebooted twice a day).