From: Yang Shi <yang.shi@linux.alibaba.com>
To: mhocko@kernel.org, willy@infradead.org,
ldufour@linux.vnet.ibm.com, vbabka@suse.cz,
akpm@linux-foundation.org, dave.hansen@intel.com,
oleg@redhat.com, srikar@linux.vnet.ibm.com
Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [RFC v9 PATCH 3/4] mm: unmap VM_HUGETLB mappings with optimized path
Date: Wed, 12 Sep 2018 04:58:12 +0800 [thread overview]
Message-ID: <1536699493-69195-4-git-send-email-yang.shi@linux.alibaba.com> (raw)
In-Reply-To: <1536699493-69195-1-git-send-email-yang.shi@linux.alibaba.com>
When unmapping VM_HUGETLB 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>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
---
mm/mmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 937d2f2..086f8b5 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2812,12 +2812,12 @@ static int do_munmap_zap_rlock(struct mm_struct *mm, unsigned long start,
}
/*
- * Unmapping vmas, which have VM_HUGETLB or VM_PFNMAP
+ * Unmapping vmas, which have VM_PFNMAP
* need get done with write mmap_sem held since they may update
* vm_flags. Deal with such mappings with regular do_munmap() call.
*/
for (vma = start_vma; vma && vma->vm_start < end; vma = vma->vm_next) {
- if (vma->vm_flags & (VM_HUGETLB | VM_PFNMAP))
+ if (vma->vm_flags & VM_PFNMAP)
goto regular_path;
}
--
1.8.3.1
next prev parent reply other threads:[~2018-09-11 20:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-11 20:58 [RFC v9 PATCH 0/4] mm: zap pages with read mmap_sem in munmap for large mapping Yang Shi
2018-09-11 20:58 ` [RFC v9 PATCH 1/4] mm: refactor do_munmap() to extract the common part Yang Shi
2018-09-11 20:58 ` [RFC v9 PATCH 2/4] mm: mmap: zap pages with read mmap_sem in munmap Yang Shi
2018-09-11 21:16 ` Matthew Wilcox
2018-09-11 23:35 ` Yang Shi
2018-09-12 2:29 ` Matthew Wilcox
2018-09-12 9:11 ` Michal Hocko
2018-09-12 17:15 ` Yang Shi
2018-09-11 20:58 ` Yang Shi [this message]
2018-09-11 20:58 ` [RFC v9 PATCH 4/4] mm: unmap VM_PFNMAP mappings with optimized path Yang Shi
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