Messages in this thread | | | Date | Tue, 5 Sep 2023 19:05:40 +0800 | Subject | Re: [PATCH 2/2] LoongArch: Use static defined zero page rather than allocated | From | bibo mao <> |
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在 2023/9/5 18:59, Huacai Chen 写道: > Hi, Bibo, > > On Tue, Sep 5, 2023 at 4:01 PM Bibo Mao <maobibo@loongson.cn> wrote: >> >> Like other popular architectures, zero page is defined in kernel >> BSS code segment, rather than dynamically alloted page. It is >> simpler. >> >> Signed-off-by: Bibo Mao <maobibo@loongson.cn> >> --- >> arch/loongarch/include/asm/mmzone.h | 2 -- >> arch/loongarch/include/asm/pgtable.h | 6 ++---- >> arch/loongarch/kernel/numa.c | 1 - >> arch/loongarch/mm/init.c | 21 +-------------------- >> 4 files changed, 3 insertions(+), 27 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 342c5f9c25d2..70bd57daf42a 100644 >> --- a/arch/loongarch/include/asm/pgtable.h >> +++ b/arch/loongarch/include/asm/pgtable.h >> @@ -70,10 +70,8 @@ struct vm_area_struct; >> * for zero-mapped memory areas etc.. >> */ >> >> -extern unsigned long empty_zero_page; >> - >> -#define ZERO_PAGE(vaddr) \ >> - (virt_to_page((void *)(empty_zero_page))) >> +extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; >> +#define ZERO_PAGE(vaddr) ((void)(vaddr), virt_to_page(empty_zero_page)) > Can we simply use virt_to_page(empty_zero_page) here? Only x86 does it > like this now. will do in next patch.
Regards Bibo Mao > > Huacai >> >> /* >> * 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 8ec668f97b00..628ebe42b519 100644 >> --- a/arch/loongarch/mm/init.c >> +++ b/arch/loongarch/mm/init.c >> @@ -35,27 +35,9 @@ >> #include <asm/pgalloc.h> >> #include <asm/tlb.h> >> >> -unsigned long empty_zero_page; >> +unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; >> EXPORT_SYMBOL(empty_zero_page); >> >> -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); >> - >> -} >> - >> void copy_user_highpage(struct page *to, struct page *from, >> unsigned long vaddr, struct vm_area_struct *vma) >> { >> @@ -99,7 +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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