diff options
author | Song Liu | 2018-08-18 00:47:00 +0200 |
---|---|---|
committer | Linus Torvalds | 2018-08-18 01:20:30 +0200 |
commit | 50f8b92f21d23789bd4ada593e8ddc56cc4f79fe (patch) | |
tree | ac23602fa31f41df2466e584f6e024364f10f888 /kernel/memremap.c | |
parent | mm/fadvise.c: fix signed overflow UBSAN complaint (diff) | |
download | kernel-qcow2-linux-50f8b92f21d23789bd4ada593e8ddc56cc4f79fe.tar.gz kernel-qcow2-linux-50f8b92f21d23789bd4ada593e8ddc56cc4f79fe.tar.xz kernel-qcow2-linux-50f8b92f21d23789bd4ada593e8ddc56cc4f79fe.zip |
mm: thp: pass correct vm_flags to hugepage_vma_check()
khugepaged_enter_vma_merge() passes a stale vma->vm_flags to
hugepage_vma_check(). The argument vm_flags contains the latest value.
Therefore, it is necessary to pass this vm_flags into
hugepage_vma_check().
With this bug, madvise(MADV_HUGEPAGE) for mmap files in shmem fails to
put memory in huge pages. Here is an example of failed madvise():
/* mount /dev/shm with huge=advise:
* mount -o remount,huge=advise /dev/shm */
/* create file /dev/shm/huge */
#define HUGE_FILE "/dev/shm/huge"
fd = open(HUGE_FILE, O_RDONLY);
ptr = mmap(NULL, FILE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0);
ret = madvise(ptr, FILE_SIZE, MADV_HUGEPAGE);
madvise() will return 0, but this memory region is never put in huge
page (check from /proc/meminfo: ShmemHugePages).
Link: http://lkml.kernel.org/r/20180629181752.792831-1-songliubraving@fb.com
Fixes: 02b75dc8160d ("mm: thp: register mm for khugepaged when merging vma for shmem")
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/memremap.c')
0 files changed, 0 insertions, 0 deletions