Re: [RFC PATCH 6/9] mm: export-GPL get_pageblock_migratetype

[Christoph Hellwig]

On Thu, Apr 09, 2020 at 03:35:40PM -0400, Mathieu Desnoyers wrote:
> The macro include/linux/mmzone.h:get_pageblock_migratetype() uses
> the symbol get_pfnblock_flags_mask, which is not exported. That macro is
> used within the kmem and page_ref trace events to trace the migrate type
> of the target page.
> 
> Exporting this symbol to GPL modules allows GPL kernel tracers to be
> implemented as modules.

Which might make some sense if we had such intree modules (and then even
some as we could have higher level functions).  Without that is
obviously is a no-go.