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mm/vma: append unlikely() while testing VMA access permissions

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It is unlikely that an inaccessible VMA without required permission flags
will get a page fault.  Hence lets just append unlikely() directive to
such checks in order to improve performance while also standardizing it
across various platforms.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Link: http://lkml.kernel.org/r/1582525304-32113-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Anshuman Khandual 2020-04-06 20:03:59 -07:00 committed by Linus Torvalds
parent a0137f16df
commit 5093c5872b
3 changed files with 3 additions and 3 deletions
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2
arch/csky/mm/fault.c
View file

@ -141,7 +141,7 @@ good_area:
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!vma_is_accessible(vma))
if (unlikely(!vma_is_accessible(vma)))
goto bad_area;
}

2
arch/m68k/mm/fault.c
View file

@ -125,7 +125,7 @@ good_area:
case 1: /* read, present */
goto acc_err;
case 0: /* read, not present */
if (!vma_is_accessible(vma))
if (unlikely(!vma_is_accessible(vma)))
goto acc_err;
}

2
arch/mips/mm/fault.c
View file

@ -142,7 +142,7 @@ good_area:
goto bad_area;
}
} else {
if (!vma_is_accessible(vma))
if (unlikely(!vma_is_accessible(vma)))
goto bad_area;
}
}