mm/khugepaged.c:2181:13: warning: stack frame size (3808) exceeds limit (2048) in 'khugepaged_do_scan'

From: kernel test robot
Date: Fri Nov 26 2021 - 07:43:44 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: a4849f6000e29235a2707f22e39da6b897bb9543
commit: 2b5067a8143e34aa3fa57a20fb8a3c40d905f942 mm: mmap_lock: add tracepoints around lock acquisition
date: 12 months ago
config: mips-randconfig-r013-20211124 (https://download.01.org/0day-ci/archive/20211126/202111262010.UBcefCrE-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 67a1c45def8a75061203461ab0060c75c864df1c)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install mips cross compiling tool for clang build
# apt-get install binutils-mips-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2b5067a8143e34aa3fa57a20fb8a3c40d905f942
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2b5067a8143e34aa3fa57a20fb8a3c40d905f942
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> mm/khugepaged.c:2181:13: warning: stack frame size (3808) exceeds limit (2048) in 'khugepaged_do_scan' [-Wframe-larger-than]
static void khugepaged_do_scan(void)
^
1 warning generated.
Assembler messages:
Warning: a different -march was already specified, is now octeon


vim +/khugepaged_do_scan +2181 mm/khugepaged.c

b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2180
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 @2181 static void khugepaged_do_scan(void)
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2182 {
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2183 struct page *hpage = NULL;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2184 unsigned int progress = 0, pass_through_head = 0;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2185 unsigned int pages = khugepaged_pages_to_scan;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2186 bool wait = true;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2187
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2188 barrier(); /* write khugepaged_pages_to_scan to local stack */
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2189
a980df33e9351e Kirill A. Shutemov 2020-06-03 2190 lru_add_drain_all();
a980df33e9351e Kirill A. Shutemov 2020-06-03 2191
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2192 while (progress < pages) {
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2193 if (!khugepaged_prealloc_page(&hpage, &wait))
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2194 break;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2195
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2196 cond_resched();
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2197
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2198 if (unlikely(kthread_should_stop() || try_to_freeze()))
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2199 break;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2200
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2201 spin_lock(&khugepaged_mm_lock);
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2202 if (!khugepaged_scan.mm_slot)
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2203 pass_through_head++;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2204 if (khugepaged_has_work() &&
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2205 pass_through_head < 2)
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2206 progress += khugepaged_scan_mm_slot(pages - progress,
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2207 &hpage);
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2208 else
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2209 progress = pages;
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2210 spin_unlock(&khugepaged_mm_lock);
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2211 }
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2212
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2213 if (!IS_ERR_OR_NULL(hpage))
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2214 put_page(hpage);
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2215 }
b46e756f5e4703 Kirill A. Shutemov 2016-07-26 2216

:::::: The code at line 2181 was first introduced by commit
:::::: b46e756f5e47031c67658ff036e5ffe27062fa43 thp: extract khugepaged from mm/huge_memory.c

:::::: TO: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
:::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx