lkml.org 
[lkml]   [2022]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 4/6] mm: hugetlb_vmemmap: add missing smp_wmb() before set_pte_at()
From


On 8/16/2022 9:05 PM, Miaohe Lin wrote:
> The memory barrier smp_wmb() is needed to make sure that preceding stores
> to the page contents become visible before the below set_pte_at() write.
>
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>

Regards
Yin, Fengwei

> ---
> mm/hugetlb_vmemmap.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> index 20f414c0379f..76b2d03a0d8d 100644
> --- a/mm/hugetlb_vmemmap.c
> +++ b/mm/hugetlb_vmemmap.c
> @@ -287,6 +287,11 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
> copy_page(to, (void *)walk->reuse_addr);
> reset_struct_pages(to);
>
> + /*
> + * Makes sure that preceding stores to the page contents become visible
> + * before the set_pte_at() write.
> + */
> + smp_wmb();
> set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot));
> }
>

\
 
 \ /
  Last update: 2022-08-18 03:16    [W:0.286 / U:0.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site