On Fri 11-10-19 13:29:32, Andrew Morton wrote: > alloc_gigantic_page() implements an allocation method where it scans over > various zones looking for a large contiguous memory block which could not > have been allocated through the buddy allocator. A subsequent patch which > tests arch page table helpers needs such a method to allocate PUD_SIZE > sized memory block. In the future such methods might have other use cases > as well. So alloc_gigantic_page() has been split carving out actual > memory allocation method and made available via new > alloc_gigantic_page_order(). You are exporting a helper used for hugetlb internally. Is this really what is needed? I haven't followed this patchset but don't you simply need a generic 1GB allocator? If yes then you should be looking at alloc_contig_range. Or did I miss the point you really want hugetlb page? > Link: http://lkml.kernel.org/r/1570775142-31425-2-git-send-email-anshuman.khandual@xxxxxxx > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > Cc: Vlastimil Babka <vbabka@xxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> > Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > Cc: Jason Gunthorpe <jgg@xxxxxxxx> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Mark Brown <broonie@xxxxxxxxxx> > Cc: Steven Price <Steven.Price@xxxxxxx> > Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > Cc: Sri Krishna chowdary <schowdary@xxxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxx> > Cc: Russell King - ARM Linux <linux@xxxxxxxxxxxxxxx> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Cc: Paul Mackerras <paulus@xxxxxxxxx> > Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> > Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> > Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx> > Cc: James Hogan <jhogan@xxxxxxxxxx> > Cc: Paul Burton <paul.burton@xxxxxxxx> > Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> > Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> > Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> > Cc: Christophe Leroy <christophe.leroy@xxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > include/linux/hugetlb.h | 9 +++++++++ > mm/hugetlb.c | 24 ++++++++++++++++++++++-- > 2 files changed, 31 insertions(+), 2 deletions(-) > > --- a/include/linux/hugetlb.h~mm-hugetlb-make-alloc_gigantic_page-available-for-general-use > +++ a/include/linux/hugetlb.h > @@ -299,6 +299,9 @@ static inline bool is_file_hugepages(str > } > > > +struct page * > +alloc_gigantic_page_order(unsigned int order, gfp_t gfp_mask, > + int nid, nodemask_t *nodemask); > #else /* !CONFIG_HUGETLBFS */ > > #define is_file_hugepages(file) false > @@ -310,6 +313,12 @@ hugetlb_file_setup(const char *name, siz > return ERR_PTR(-ENOSYS); > } > > +static inline struct page * > +alloc_gigantic_page_order(unsigned int order, gfp_t gfp_mask, > + int nid, nodemask_t *nodemask) > +{ > + return NULL; > +} > #endif /* !CONFIG_HUGETLBFS */ > > #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA > --- a/mm/hugetlb.c~mm-hugetlb-make-alloc_gigantic_page-available-for-general-use > +++ a/mm/hugetlb.c > @@ -1112,10 +1112,9 @@ static bool zone_spans_last_pfn(const st > return zone_spans_pfn(zone, last_pfn); > } > > -static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, > +struct page *alloc_gigantic_page_order(unsigned int order, gfp_t gfp_mask, > int nid, nodemask_t *nodemask) > { > - unsigned int order = huge_page_order(h); > unsigned long nr_pages = 1 << order; > unsigned long ret, pfn, flags; > struct zonelist *zonelist; > @@ -1151,6 +1150,14 @@ static struct page *alloc_gigantic_page( > return NULL; > } > > +static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, > + int nid, nodemask_t *nodemask) > +{ > + unsigned int order = huge_page_order(h); > + > + return alloc_gigantic_page_order(order, gfp_mask, nid, nodemask); > +} > + > static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); > static void prep_compound_gigantic_page(struct page *page, unsigned int order); > #else /* !CONFIG_CONTIG_ALLOC */ > @@ -1159,6 +1166,12 @@ static struct page *alloc_gigantic_page( > { > return NULL; > } > + > +struct page *alloc_gigantic_page_order(unsigned int order, gfp_t gfp_mask, > + int nid, nodemask_t *nodemask) > +{ > + return NULL; > +} > #endif /* CONFIG_CONTIG_ALLOC */ > > #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ > @@ -1167,6 +1180,13 @@ static struct page *alloc_gigantic_page( > { > return NULL; > } > + > +struct page *alloc_gigantic_page_order(unsigned int order, gfp_t gfp_mask, > + int nid, nodemask_t *nodemask) > +{ > + return NULL; > +} > + > static inline void free_gigantic_page(struct page *page, unsigned int order) { } > static inline void destroy_compound_gigantic_page(struct page *page, > unsigned int order) { } > _ > > Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are > > mm-hugetlb-make-alloc_gigantic_page-available-for-general-use.patch > mm-debug-add-tests-validating-architecture-page-table-helpers.patch > mm-hotplug-reorder-memblock_-calls-in-try_remove_memory.patch -- Michal Hocko SUSE Labs
