It's awful. I have a v6 in the works which fixes a number of problems in v5, but there are about ten Kconfig options which the x86 code depends on. And then ... yes, there's this bad definition of pud_t on ARM. Arnd has a patch to fix that problem, Subject: [PATCH v2] [RFC] ARM: modify pgd_t definition for TRANSPARENT_HUGEPAGE_PUD. But 0day is still pointing out other problems with the current patchset, so I'd hold off on it until I get v6 posted if I were you. Thanks for picking up x86-unify-native__get_and_clear-smp-case.patch -----Original Message----- From: Andrew Morton [mailto:akpm@xxxxxxxxxxxxxxxxxxxx] Sent: Tuesday, March 29, 2016 3:17 PM To: Wilcox, Matthew R Cc: Matthew Wilcox; linux-mm@xxxxxxxxx; linux-nvdimm@xxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx Subject: Re: [PATCH v4 3/8] mm: Add support for PUD-sized transparent hugepages On Sun, 31 Jan 2016 23:09:30 +1100 Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx> wrote: > From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx> > > The current transparent hugepage code only supports PMDs. This patch > adds support for transparent use of PUDs with DAX. It does not include > support for anonymous pages. > > Most of this patch simply parallels the work that was done for huge PMDs. > The only major difference is how the new ->pud_entry method in mm_walk > works. The ->pmd_entry method replaces the ->pte_entry method, whereas > the ->pud_entry method works along with either ->pmd_entry or ->pte_entry. > The pagewalk code takes care of locking the PUD before calling ->pud_walk, > so handlers do not need to worry whether the PUD is stable. Why is this patchset always so hard to compile :( > ... > > --- a/include/linux/pfn_t.h > +++ b/include/linux/pfn_t.h > @@ -82,6 +82,13 @@ static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot) > { > return pfn_pmd(pfn_t_to_pfn(pfn), pgprot); > } > + > +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > +static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot) > +{ > + return pfn_pud(pfn_t_to_pfn(pfn), pgprot); > +} > +#endif > #endif > > #ifdef __HAVE_ARCH_PTE_DEVMAP > @@ -98,5 +105,6 @@ static inline bool pfn_t_devmap(pfn_t pfn) > } > pte_t pte_mkdevmap(pte_t pte); > pmd_t pmd_mkdevmap(pmd_t pmd); > +pud_t pud_mkdevmap(pud_t pud); arm allnoconfig: In file included from kernel/memremap.c:17: include/linux/pfn_t.h:107: error: 'pud_mkdevmap' declared as function returning an array because it expands to pgd_t pud_mkdevmap(pgd_t pud); and typedef unsigned long pgd_t[2]; Also the patch provides no implementation of pud_mkdevmap() so it's obviously going to break bisection. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
