Messages in this thread | | | Subject | Re: [PATCH v3 1/6] mm/thp: add prep_transhuge_device_private_page() | From | Ralph Campbell <> | Date | Fri, 6 Nov 2020 12:56:47 -0800 |
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On 11/5/20 11:55 PM, Christoph Hellwig wrote: > On Thu, Nov 05, 2020 at 04:51:42PM -0800, Ralph Campbell wrote: >> +extern void prep_transhuge_device_private_page(struct page *page); > > No need for the extern.
Right, I was just copying the style. Would you like to see a preparatory patch that removes extern for the other declarations in huge_mm.h?
>> +static inline void prep_transhuge_device_private_page(struct page *page) >> +{ >> +} > > Is the code to call this even reachable if THP support is configured > out? If not just declaring it unconditionally and letting dead code > elimination do its job might be a tad cleaner.
The HMM test driver depends on TRANSPARENT_HUGEPAGE but the nouveau SVM option doesn't and SVM is still useful if TRANSPARENT_HUGEPAGE is not configured.
The problem with defining prep_transhuge_device_private_page() in huge_mm.h as a static inline function is that prep_compound_page() and prep_transhuge_page() would have to be EXPORT_SYMBOL_GPL which are currently mm internal only. The intent is to make this helper callable by separate device driver modules using struct pages created with memremap_pages().
>> +void prep_transhuge_device_private_page(struct page *page) > > I think a kerneldoc comment explaining what this function is useful for > would be helpful.
That is a good idea. I'll add it to v4.
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