Messages in this thread | | | From | Huacai Chen <> | Date | Thu, 7 Sep 2023 09:37:22 +0800 | Subject | Re: [PATCH v2] LoongArch: Code cleanup with zero page |
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Queued for loongarch-next with the old title "LoongArch: Use static defined zero page rather than allocated" since it is more clear, thanks.
Huacai
On Thu, Sep 7, 2023 at 9:22 AM Bibo Mao <maobibo@loongson.cn> wrote: > > Like other popular architectures, zero page is defined in kernel > BSS data segment, rather than dynamically allocated. It is simpler. > Also this patch removes macro __HAVE_COLOR_ZERO_PAGE and variable > zero_page_mask since there is only one page for zeo_page usage. > > Signed-off-by: Bibo Mao <maobibo@loongson.cn> > --- > Changes in v2: > 1. Combine two simple patches into one > 2. Refine implementation about macro ZERO_PAGE(vaddr) > > --- > arch/loongarch/include/asm/mmzone.h | 2 -- > arch/loongarch/include/asm/pgtable.h | 9 ++------- > arch/loongarch/kernel/numa.c | 1 - > arch/loongarch/mm/init.c | 28 +--------------------------- > 4 files changed, 3 insertions(+), 37 deletions(-) > > diff --git a/arch/loongarch/include/asm/mmzone.h b/arch/loongarch/include/asm/mmzone.h > index fe67d0b4b33d..2b9a90727e19 100644 > --- a/arch/loongarch/include/asm/mmzone.h > +++ b/arch/loongarch/include/asm/mmzone.h > @@ -13,6 +13,4 @@ extern struct pglist_data *node_data[]; > > #define NODE_DATA(nid) (node_data[(nid)]) > > -extern void setup_zero_pages(void); > - > #endif /* _ASM_MMZONE_H_ */ > diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h > index 06963a172319..189156d8435c 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -69,13 +69,8 @@ struct vm_area_struct; > * ZERO_PAGE is a global shared page that is always zero; used > * for zero-mapped memory areas etc.. > */ > - > -extern unsigned long empty_zero_page; > -extern unsigned long zero_page_mask; > - > -#define ZERO_PAGE(vaddr) \ > - (virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))) > -#define __HAVE_COLOR_ZERO_PAGE > +extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > +#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > > /* > * TLB refill handlers may also map the vmalloc area into xkvrange. > diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c > index 708665895b47..6f464d49f0c2 100644 > --- a/arch/loongarch/kernel/numa.c > +++ b/arch/loongarch/kernel/numa.c > @@ -470,7 +470,6 @@ void __init mem_init(void) > { > high_memory = (void *) __va(get_num_physpages() << PAGE_SHIFT); > memblock_free_all(); > - setup_zero_pages(); /* This comes from node 0 */ > } > > int pcibus_to_node(struct pci_bus *bus) > diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c > index 3b7d8129570b..628ebe42b519 100644 > --- a/arch/loongarch/mm/init.c > +++ b/arch/loongarch/mm/init.c > @@ -35,33 +35,8 @@ > #include <asm/pgalloc.h> > #include <asm/tlb.h> > > -/* > - * We have up to 8 empty zeroed pages so we can map one of the right colour > - * when needed. Since page is never written to after the initialization we > - * don't have to care about aliases on other CPUs. > - */ > -unsigned long empty_zero_page, zero_page_mask; > +unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; > EXPORT_SYMBOL(empty_zero_page); > -EXPORT_SYMBOL(zero_page_mask); > - > -void setup_zero_pages(void) > -{ > - unsigned int order, i; > - struct page *page; > - > - order = 0; > - > - empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); > - if (!empty_zero_page) > - panic("Oh boy, that early out of memory?"); > - > - page = virt_to_page((void *)empty_zero_page); > - split_page(page, order); > - for (i = 0; i < (1 << order); i++, page++) > - mark_page_reserved(page); > - > - zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; > -} > > void copy_user_highpage(struct page *to, struct page *from, > unsigned long vaddr, struct vm_area_struct *vma) > @@ -106,7 +81,6 @@ void __init mem_init(void) > high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); > > memblock_free_all(); > - setup_zero_pages(); /* Setup zeroed pages. */ > } > #endif /* !CONFIG_NUMA */ > > -- > 2.27.0 > >
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