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Re: [Xen-devel] [PATCH] linux/balloon: prefer using pages from balloon i

To: <dave.mccracken@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] linux/balloon: prefer using pages from balloon in alloc_empty_pages_and_pagevec()
From: "Jan Beulich" <JBeulich@xxxxxxxxxx>
Date: Wed, 16 Dec 2009 15:32:35 +0000
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx
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>>> "Jan Beulich" <JBeulich@xxxxxxxxxx> 16.12.09 16:13 >>>
>Likely also something that could be done in the pv-ops tree (though it
>would need some adjustment to deal with the balloon_order!=0 case).

... which seems to be broken at present anyway: The main loops in
{alloc,free}_empty_pages_and_pagevec() both did not get their
upper bound updated correctly (should be npages, but was left to
be nr_pages), for alloc_empty_pages_and_pagevec() the wrong value
is also being used to allocate pagevec[] (though I really think that this
shouldn't allocate more than a nr_pages vector to avoid a rather large
but unnecessary kmalloc() when nr_pages is small), and in its error
path only a single page gets freed (rather than the whole
balloon_order chunk).


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