Re: [PATCH v8 1/5] mm: introduce a common interface for balloonpages mobility

[Rafael Aquini]

On Thu, Aug 23, 2012 at 12:03:15PM -0400, Rik van Riel wrote:
> >
> >Not "longer" - apparently forever unless user resend the leak command.
> >It's wrong - it should
> >1. not tell host if nothing was done
> >2. after migration finished leak and tell host
> 
> Agreed.  If the balloon is told to leak N pages, and could
> not do so because those pages were locked, the balloon driver
> needs to retry (maybe waiting on a page lock?) and not signal
> completion until after the job has been completed.
> 
> Having the balloon driver wait on the page lock should be
> fine, because compaction does not hold the page lock for
> long.

And that is precisely what leak_balloon is doing. When it stumbles across a
locked page it gets rid of that leak round to give a shot for compaction to
finish its task.


--
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/