Re: [PATCH 1/2] slab: __GFP_ZERO is incompatible with a constructor

[Christopher Lameter]

On Tue, 10 Apr 2018, Matthew Wilcox wrote:

> __GFP_ZERO requests that the object be initialised to all-zeroes,
> while the purpose of a constructor is to initialise an object to a
> particular pattern.  We cannot do both.  Add a warning to catch any
> users who mistakenly pass a __GFP_ZERO flag when allocating a slab with
> a constructor.

Can we move this check out of the critical paths and check for
a ctor and GFP_ZERO when calling the page allocator? F.e. in
allocate_slab()?