Re: [linux-next:master 7735/7934] mm/hugetlb.c:5565:14: warning: variable 'reserve_alloc' set but not used

[Mike Kravetz <mike.kravetz@oracle.com>]

On 09/20/22 06:30, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   4c9ca5b1597e3222177ba2a94658f78fa5ef4f58
> commit: 449f4bb2cb94b16a2014eeef41f4a50c8a3ecbdc [7735/7934] hugetlb: clean up code checking for fault/truncation races
> config: i386-defconfig (https://download.01.org/0day-ci/archive/20220920/202209200603.Hpvoa8Ii-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
> reproduce (this is a W=1 build):
>         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=449f4bb2cb94b16a2014eeef41f4a50c8a3ecbdc
>         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>         git fetch --no-tags linux-next master
>         git checkout 449f4bb2cb94b16a2014eeef41f4a50c8a3ecbdc
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
>    mm/hugetlb.c: In function 'hugetlb_no_page':
> >> mm/hugetlb.c:5565:14: warning: variable 'reserve_alloc' set but not used [-Wunused-but-set-variable]
>     5565 |         bool reserve_alloc = false;
>          |              ^~~~~~~~~~~~~

Below patch will address warning,

From 99366ab6e4d84426069f44f134921b3601ec1cbf Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz@oracle.com>
Date: Mon, 19 Sep 2022 16:23:24 -0700
Subject: [PATCH] hugetlb: fix reserve_alloc set but not used compiler warning

Error path code checking the reserve_alloc variable was removed as it
was determined it was not necessary.  However, the variable itself was
not removed at the same time.  Remove now.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
---
 mm/hugetlb.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9b8526d27c29..0c3c2c5ef994 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5536,7 +5536,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 	spinlock_t *ptl;
 	unsigned long haddr = address & huge_page_mask(h);
 	bool new_page, new_pagecache_page = false;
-	bool reserve_alloc = false;
 
 	/*
 	 * Currently, we are forced to kill the process in the event the
@@ -5592,8 +5591,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 		clear_huge_page(page, address, pages_per_huge_page(h));
 		__SetPageUptodate(page);
 		new_page = true;
-		if (HPageRestoreReserve(page))
-			reserve_alloc = true;
 
 		if (vma->vm_flags & VM_MAYSHARE) {
 			int err = hugetlb_add_to_page_cache(page, mapping, idx);
-- 
2.37.3