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Date: Thu, 1 Jun 2017 11:37:07 -0700 (PDT)
From: Hugh Dickins <hughd@google.com>
To: Christoph Lameter <cl@linux.com>
cc: Hugh Dickins <hughd@google.com>, Michael Ellerman <mpe@ellerman.id.au>,
 "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
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Subject: Re: 4.12-rc ppc64 4k-page needs costly allocations
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On Thu, 1 Jun 2017, Christoph Lameter wrote:
> 
> Ok so debugging was off but the slab cache has a ctor callback which
> mandates that the free pointer cannot use the free object space when
> the object is not in use. Thus the size of the object must be increased to
> accomodate the freepointer.

Thanks a lot for working that out.  Makes sense, fully understood now,
nothing to worry about (though makes one wonder whether it's efficient
to use ctors on high-alignment caches; or whether an internal "zero-me"
ctor would be useful).

Hugh