Messages in this thread | | | Date | Mon, 26 Apr 2010 18:48:42 +0900 | Subject | Re: [BUGFIX][mm][PATCH] fix migration race in rmap_walk | From | Minchan Kim <> |
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On Mon, Apr 26, 2010 at 6:28 PM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > On Mon, 26 Apr 2010 08:49:01 +0900 > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > >> On Sat, 24 Apr 2010 11:43:24 +0100 >> Mel Gorman <mel@csn.ul.ie> wrote: > >> > It looks nice but it still broke after 28 hours of running. The >> > seq-counter is still insufficient to catch all changes that are made to >> > the list. I'm beginning to wonder if a) this really can be fully safely >> > locked with the anon_vma changes and b) if it has to be a spinlock to >> > catch the majority of cases but still a lazy cleanup if there happens to >> > be a race. It's unsatisfactory and I'm expecting I'll either have some >> > insight to the new anon_vma changes that allow it to be locked or Rik >> > knows how to restore the original behaviour which as Andrea pointed out >> > was safe. >> > >> Ouch. > > Ok, reproduced. Here is status in my test + printk(). > > * A race doesn't seem to happen if swap=off. > I need to swapon to cause the bug
FYI,
Do you have a swapon/off bomb test? When I saw your mail, I feel it might be culprit.
http://lkml.org/lkml/2010/4/22/762.
It is just guessing. I don't have a time to look into, now.
-- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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