+ mm-page_allocc-micro-optimisation-remove-unnecessary-branch.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/page_alloc.c: micro-optimisation Remove unnecessary branch
has been added to the -mm tree.  Its filename is
     mm-page_allocc-micro-optimisation-remove-unnecessary-branch.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-page_allocc-micro-optimisation-remove-unnecessary-branch.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_allocc-micro-optimisation-remove-unnecessary-branch.patch

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------------------------------------------------------
From: Mateusz Nosek <mateusznosek0@gmail.com>
Subject: mm/page_alloc.c: micro-optimisation Remove unnecessary branch

Previously if branch condition was false, the assignment was not executed.
The assignment can be safely executed even when the condition is false
and it is not incorrect as it assigns the value of 'nodemask' to
'ac.nodemask' which already has the same value.

So as the assignment can be executed unconditionally, the branch can be
removed.

Link: http://lkml.kernel.org/r/20200307225335.31300-1-mateusznosek0@gmail.com
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/mm/page_alloc.c~mm-page_allocc-micro-optimisation-remove-unnecessary-branch
+++ a/mm/page_alloc.c
@@ -4764,8 +4764,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, u
 	 * Restore the original nodemask if it was potentially replaced with
 	 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
 	 */
-	if (unlikely(ac.nodemask != nodemask))
-		ac.nodemask = nodemask;
+	ac.nodemask = nodemask;
 
 	page = __alloc_pages_slowpath(alloc_mask, order, &ac);
 
_

Patches currently in -mm which might be from mateusznosek0@gmail.com are

mm-micro-optimisation-save-two-branches-on-hot-page-allocation-path.patch
mm-page_allocc-micro-optimisation-remove-unnecessary-branch.patch
mm-vmscanc-clean-code-by-removing-unnecessary-assignment.patch
mm-hugetlbc-clean-code-by-removing-unnecessary-initialization.patch
mm-shmemc-clean-code-by-removing-unnecessary-assignment.patch
mm-mm_initc-clean-code-use-build_bug_on-when-comparing-compile-time-constant.patch