From: Vlastimil Babka <vbabka@suse.cz>
To: Yang Shi <yang.shi@linux.alibaba.com>,
mhocko@kernel.org, willy@infradead.org,
ldufour@linux.vnet.ibm.com, kirill@shutemov.name,
akpm@linux-foundation.org
Cc: dave.hansen@intel.com, oleg@redhat.com,
srikar@linux.vnet.ibm.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [v11 PATCH 3/3] mm: unmap VM_PFNMAP mappings with optimized path
Date: Wed, 26 Sep 2018 13:11:45 +0200 [thread overview]
Message-ID: <889734e0-d2a9-3191-8d48-5c95bf29fb3f@suse.cz> (raw)
In-Reply-To: <1537376621-51150-4-git-send-email-yang.shi@linux.alibaba.com>
On 9/19/18 7:03 PM, Yang Shi wrote:
> When unmapping VM_PFNMAP mappings, vm flags need to be updated. Since
> the vmas have been detached, so it sounds safe to update vm flags with
> read mmap_sem.
>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Reviewed-by: Matthew Wilcox <willy@infradead.org>
> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
> ---
> mm/mmap.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 490340e..847a17d 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2771,15 +2771,6 @@ static int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
> munlock_vma_pages_all(tmp);
> }
>
> - /*
> - * Unmapping vmas, which have VM_HUGETLB or VM_PFNMAP,
Ah, the comment should have been already updated with the previous
patch. But nevermind as that all goes away.
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> - * need get done with write mmap_sem held since they may
> - * update vm_flags.
> - */
> - if (downgrade &&
> - (tmp->vm_flags & VM_PFNMAP))
> - downgrade = false;
> -
> tmp = tmp->vm_next;
> }
> }
>
next prev parent reply other threads:[~2018-09-26 11:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-19 17:03 [v11 PATCH 0/3] mm: zap pages with read mmap_sem in munmap for large mapping Yang Shi
2018-09-19 17:03 ` [v11 PATCH 1/3] mm: mmap: zap pages with read mmap_sem in munmap Yang Shi
2018-09-26 11:09 ` Vlastimil Babka
2018-09-19 17:03 ` [v11 PATCH 2/3] mm: unmap VM_HUGETLB mappings with optimized path Yang Shi
2018-09-26 11:10 ` Vlastimil Babka
2018-09-19 17:03 ` [v11 PATCH 3/3] mm: unmap VM_PFNMAP " Yang Shi
2018-09-26 11:11 ` Vlastimil Babka [this message]
2018-09-26 12:35 ` [v11 PATCH 0/3] mm: zap pages with read mmap_sem in munmap for large mapping Kirill A. Shutemov
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