lkml.org 
[lkml]   [2021]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 5.10 012/137] hugetlb: clear huge pte during flush function on mips platform
    Date
    From: Bibo Mao <maobibo@loongson.cn>

    [ Upstream commit 33ae8f801ad8bec48e886d368739feb2816478f2 ]

    If multiple threads are accessing the same huge page at the same
    time, hugetlb_cow will be called if one thread write the COW huge
    page. And function huge_ptep_clear_flush is called to notify other
    threads to clear the huge pte tlb entry. The other threads clear
    the huge pte tlb entry and reload it from page table, the reload
    huge pte entry may be old.

    This patch fixes this issue on mips platform, and it clears huge
    pte entry before notifying other threads to flush current huge
    page entry, it is similar with other architectures.

    Signed-off-by: Bibo Mao <maobibo@loongson.cn>
    Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/mips/include/asm/hugetlb.h | 8 +++++++-
    1 file changed, 7 insertions(+), 1 deletion(-)

    diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h
    index 10e3be870df7..c2144409c0c4 100644
    --- a/arch/mips/include/asm/hugetlb.h
    +++ b/arch/mips/include/asm/hugetlb.h
    @@ -46,7 +46,13 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
    static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
    unsigned long addr, pte_t *ptep)
    {
    - flush_tlb_page(vma, addr & huge_page_mask(hstate_vma(vma)));
    + /*
    + * clear the huge pte entry firstly, so that the other smp threads will
    + * not get old pte entry after finishing flush_tlb_page and before
    + * setting new huge pte entry
    + */
    + huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
    + flush_tlb_page(vma, addr);
    }

    #define __HAVE_ARCH_HUGE_PTE_NONE
    --
    2.30.2
    \
     
     \ /
      Last update: 2021-07-06 14:39    [W:4.408 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site