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| author | Wei Yang <richardw.yang@linux.intel.com> | 2019-11-30 17:57:39 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-01 12:59:09 -0800 |
| commit | 5d42ab293f5181609ea18f1f2ab85cd4cfc8efb2 (patch) | |
| tree | 3e9d4c41758c0478fff2fdf4b6e55ca5afd61b9b | |
| parent | 35e3d566df5ff86d19488d2cd9b49b2d9389780e (diff) | |
| download | linux-5d42ab293f5181609ea18f1f2ab85cd4cfc8efb2.tar.gz linux-5d42ab293f5181609ea18f1f2ab85cd4cfc8efb2.tar.bz2 linux-5d42ab293f5181609ea18f1f2ab85cd4cfc8efb2.zip | |
mm/mmap.c: make vma_merge() comment more easy to understand
Case 1/6, 2/7 and 3/8 have the same pattern and we handle them in the
same logic.
Rearrange the comment to make it a little easy for audience to
understand.
Link: http://lkml.kernel.org/r/20191030012445.16944-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/mmap.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index b9d0c2f3f6bf..9c648524e4dc 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1091,15 +1091,18 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags, * the area passed down from mprotect_fixup, never extending beyond one * vma, PPPPPP is the prev vma specified, and NNNNNN the next vma after: * - * AAAA AAAA AAAA AAAA - * PPPPPPNNNNNN PPPPPPNNNNNN PPPPPPNNNNNN PPPPNNNNXXXX - * cannot merge might become might become might become - * PPNNNNNNNNNN PPPPPPPPPPNN PPPPPPPPPPPP 6 or - * mmap, brk or case 4 below case 5 below PPPPPPPPXXXX 7 or - * mremap move: PPPPXXXXXXXX 8 - * AAAA - * PPPP NNNN PPPPPPPPPPPP PPPPPPPPNNNN PPPPNNNNNNNN - * might become case 1 below case 2 below case 3 below + * AAAA AAAA AAAA + * PPPPPPNNNNNN PPPPPPNNNNNN PPPPPPNNNNNN + * cannot merge might become might become + * PPNNNNNNNNNN PPPPPPPPPPNN + * mmap, brk or case 4 below case 5 below + * mremap move: + * AAAA AAAA + * PPPP NNNN PPPPNNNNXXXX + * might become might become + * PPPPPPPPPPPP 1 or PPPPPPPPPPPP 6 or + * PPPPPPPPNNNN 2 or PPPPPPPPXXXX 7 or + * PPPPNNNNNNNN 3 PPPPXXXXXXXX 8 * * It is important for case 8 that the vma NNNN overlapping the * region AAAA is never going to extended over XXXX. Instead XXXX must |