Excerpts from David Laight's message of January 25, 2021 10:24 pm: > From: Christophe Leroy >> Sent: 25 January 2021 09:15 >> >> Le 24/01/2021 à 09:22, Nicholas Piggin a écrit : >> > Support huge page vmalloc mappings. Config option HAVE_ARCH_HUGE_VMALLOC >> > enables support on architectures that define HAVE_ARCH_HUGE_VMAP and >> > supports PMD sized vmap mappings. >> > >> > vmalloc will attempt to allocate PMD-sized pages if allocating PMD size >> > or larger, and fall back to small pages if that was unsuccessful. >> > >> > Architectures must ensure that any arch specific vmalloc allocations >> > that require PAGE_SIZE mappings (e.g., module allocations vs strict >> > module rwx) use the VM_NOHUGE flag to inhibit larger mappings. >> > >> > When hugepage vmalloc mappings are enabled in the next patch, this >> > reduces TLB misses by nearly 30x on a `git diff` workload on a 2-node >> > POWER9 (59,800 -> 2,100) and reduces CPU cycles by 0.54%. >> > >> > This can result in more internal fragmentation and memory overhead for a >> > given allocation, an option nohugevmalloc is added to disable at boot. >> > >> > Signed-off-by: Nicholas Piggin <npig...@gmail.com> >> > --- >> > arch/Kconfig | 10 +++ >> > include/linux/vmalloc.h | 18 ++++ >> > mm/page_alloc.c | 5 +- >> > mm/vmalloc.c | 192 ++++++++++++++++++++++++++++++---------- >> > 4 files changed, 177 insertions(+), 48 deletions(-) >> > >> >> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> > index 0377e1d059e5..eef61e0f5170 100644 >> > --- a/mm/vmalloc.c >> > +++ b/mm/vmalloc.c >> >> > @@ -2691,15 +2746,18 @@ EXPORT_SYMBOL_GPL(vmap_pfn); >> > #endif /* CONFIG_VMAP_PFN */ >> > >> > static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, >> > - pgprot_t prot, int node) >> > + pgprot_t prot, unsigned int page_shift, >> > + int node) >> > { >> > const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; >> > - unsigned int nr_pages = get_vm_area_size(area) >> PAGE_SHIFT; >> > - unsigned long array_size; >> > - unsigned int i; >> > + unsigned int page_order = page_shift - PAGE_SHIFT; >> > + unsigned long addr = (unsigned long)area->addr; >> > + unsigned long size = get_vm_area_size(area); >> > + unsigned int nr_small_pages = size >> PAGE_SHIFT; >> > struct page **pages; >> > + unsigned int i; >> > >> > - array_size = (unsigned long)nr_pages * sizeof(struct page *); >> > + array_size = (unsigned long)nr_small_pages * sizeof(struct page *); >> >> array_size() is a function in include/linux/overflow.h >> >> For some reason, it breaks the build with your series. > > I can't see the replacement definition for array_size. > The old local variable is deleted.
Yeah I saw that after taking another look. Must have sent in a bad diff. The v11 fixed that and a couple of other compile issues. Thanks, Nick