mm: remove unnecessary local variable addr in __get_user_pages_fast()
authorWei Yang <richard.weiyang@gmail.com>
Fri, 26 Oct 2018 22:07:55 +0000 (15:07 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 26 Oct 2018 23:26:34 +0000 (16:26 -0700)
The local variable `addr' in __get_user_pages_fast() is just a shadow of
`start'.  Since `start' never changes after assignment to `addr', it is
fine to replace `start' with it.

Also the meaning of [start, end] is more obvious than [addr, end] when
passed to gup_pgd_range().

Link: http://lkml.kernel.org/r/20180925021448.20265-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/gup.c

index 1abc8b4afff65093459c43b46ebd84023fb5b66e..08eb350e0f35f36c8008bb8be8af3d2309b32025 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1780,12 +1780,11 @@ bool gup_fast_permitted(unsigned long start, int nr_pages, int write)
 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
                          struct page **pages)
 {
 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
                          struct page **pages)
 {
-       unsigned long addr, len, end;
+       unsigned long len, end;
        unsigned long flags;
        int nr = 0;
 
        start &= PAGE_MASK;
        unsigned long flags;
        int nr = 0;
 
        start &= PAGE_MASK;
-       addr = start;
        len = (unsigned long) nr_pages << PAGE_SHIFT;
        end = start + len;
 
        len = (unsigned long) nr_pages << PAGE_SHIFT;
        end = start + len;
 
@@ -1807,7 +1806,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 
        if (gup_fast_permitted(start, nr_pages, write)) {
                local_irq_save(flags);
 
        if (gup_fast_permitted(start, nr_pages, write)) {
                local_irq_save(flags);
-               gup_pgd_range(addr, end, write, pages, &nr);
+               gup_pgd_range(start, end, write, pages, &nr);
                local_irq_restore(flags);
        }
 
                local_irq_restore(flags);
        }