* Re: [PATCH 6/8] mm: shmem: add mTHP support for anonymous shmem
[not found] <adc64bf0f150bdc614c6c06fc313adeef7dbbbff.1714978902.git.baolin.wang@linux.alibaba.com>
@ 2024-05-07 10:46 ` kernel test robot
2024-05-08 6:03 ` Baolin Wang
0 siblings, 1 reply; 2+ messages in thread
From: kernel test robot @ 2024-05-07 10:46 UTC (permalink / raw)
To: Baolin Wang, akpm, hughd
Cc: llvm, oe-kbuild-all, willy, david, ioworker0, wangkefeng.wang,
ying.huang, 21cnbao, ryan.roberts, shy828301, ziy, baolin.wang,
linux-mm, linux-kernel
Hi Baolin,
kernel test robot noticed the following build warnings:
[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on next-20240506]
[cannot apply to linus/master v6.9-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Baolin-Wang/mm-move-highest_order-and-next_order-out-of-the-THP-config/20240506-164838
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/adc64bf0f150bdc614c6c06fc313adeef7dbbbff.1714978902.git.baolin.wang%40linux.alibaba.com
patch subject: [PATCH 6/8] mm: shmem: add mTHP support for anonymous shmem
config: s390-allnoconfig (https://download.01.org/0day-ci/archive/20240507/202405071820.2KY0UnDu-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 0ab4458df0688955620b72cc2c72a32dffad3615)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240507/202405071820.2KY0UnDu-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202405071820.2KY0UnDu-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from mm/shmem.c:28:
In file included from include/linux/ramfs.h:5:
In file included from include/linux/fs_parser.h:11:
In file included from include/linux/fs_context.h:14:
In file included from include/linux/security.h:33:
In file included from include/linux/mm.h:2253:
include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
514 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
>> mm/shmem.c:1780:10: warning: variable 'folio' is used uninitialized whenever 'while' loop exits because its condition is false [-Wsometimes-uninitialized]
1780 | while (suitable_orders) {
| ^~~~~~~~~~~~~~~
mm/shmem.c:1795:7: note: uninitialized use occurs here
1795 | if (!folio)
| ^~~~~
mm/shmem.c:1780:10: note: remove the condition if it is always true
1780 | while (suitable_orders) {
| ^~~~~~~~~~~~~~~
| 1
mm/shmem.c:1750:21: note: initialize the variable 'folio' to silence this warning
1750 | struct folio *folio;
| ^
| = NULL
mm/shmem.c:1564:20: warning: unused function 'shmem_show_mpol' [-Wunused-function]
1564 | static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol)
| ^~~~~~~~~~~~~~~
3 warnings generated.
vim +1780 mm/shmem.c
1741
1742 static struct folio *shmem_alloc_and_add_folio(struct vm_fault *vmf,
1743 gfp_t gfp, struct inode *inode, pgoff_t index,
1744 struct mm_struct *fault_mm, bool huge, unsigned long orders)
1745 {
1746 struct address_space *mapping = inode->i_mapping;
1747 struct shmem_inode_info *info = SHMEM_I(inode);
1748 struct vm_area_struct *vma = vmf ? vmf->vma : NULL;
1749 unsigned long suitable_orders;
1750 struct folio *folio;
1751 long pages;
1752 int error, order;
1753
1754 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
1755 huge = false;
1756
1757 if (huge || orders > 0) {
1758 if (vma && vma_is_anon_shmem(vma) && orders) {
1759 suitable_orders = anon_shmem_suitable_orders(inode, vmf,
1760 mapping, index, orders);
1761 } else {
1762 pages = HPAGE_PMD_NR;
1763 suitable_orders = BIT(HPAGE_PMD_ORDER);
1764 index = round_down(index, HPAGE_PMD_NR);
1765
1766 /*
1767 * Check for conflict before waiting on a huge allocation.
1768 * Conflict might be that a huge page has just been allocated
1769 * and added to page cache by a racing thread, or that there
1770 * is already at least one small page in the huge extent.
1771 * Be careful to retry when appropriate, but not forever!
1772 * Elsewhere -EEXIST would be the right code, but not here.
1773 */
1774 if (xa_find(&mapping->i_pages, &index,
1775 index + HPAGE_PMD_NR - 1, XA_PRESENT))
1776 return ERR_PTR(-E2BIG);
1777 }
1778
1779 order = highest_order(suitable_orders);
> 1780 while (suitable_orders) {
1781 pages = 1 << order;
1782 index = round_down(index, pages);
1783 folio = shmem_alloc_hugefolio(gfp, info, index, order);
1784 if (folio)
1785 goto allocated;
1786
1787 if (pages == HPAGE_PMD_NR)
1788 count_vm_event(THP_FILE_FALLBACK);
1789 order = next_order(&suitable_orders, order);
1790 }
1791 } else {
1792 pages = 1;
1793 folio = shmem_alloc_folio(gfp, info, index);
1794 }
1795 if (!folio)
1796 return ERR_PTR(-ENOMEM);
1797
1798 allocated:
1799 __folio_set_locked(folio);
1800 __folio_set_swapbacked(folio);
1801
1802 gfp &= GFP_RECLAIM_MASK;
1803 error = mem_cgroup_charge(folio, fault_mm, gfp);
1804 if (error) {
1805 if (xa_find(&mapping->i_pages, &index,
1806 index + pages - 1, XA_PRESENT)) {
1807 error = -EEXIST;
1808 } else if (pages == HPAGE_PMD_NR) {
1809 count_vm_event(THP_FILE_FALLBACK);
1810 count_vm_event(THP_FILE_FALLBACK_CHARGE);
1811 }
1812 goto unlock;
1813 }
1814
1815 error = shmem_add_to_page_cache(folio, mapping, index, NULL, gfp);
1816 if (error)
1817 goto unlock;
1818
1819 error = shmem_inode_acct_blocks(inode, pages);
1820 if (error) {
1821 struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
1822 long freed;
1823 /*
1824 * Try to reclaim some space by splitting a few
1825 * large folios beyond i_size on the filesystem.
1826 */
1827 shmem_unused_huge_shrink(sbinfo, NULL, 2);
1828 /*
1829 * And do a shmem_recalc_inode() to account for freed pages:
1830 * except our folio is there in cache, so not quite balanced.
1831 */
1832 spin_lock(&info->lock);
1833 freed = pages + info->alloced - info->swapped -
1834 READ_ONCE(mapping->nrpages);
1835 if (freed > 0)
1836 info->alloced -= freed;
1837 spin_unlock(&info->lock);
1838 if (freed > 0)
1839 shmem_inode_unacct_blocks(inode, freed);
1840 error = shmem_inode_acct_blocks(inode, pages);
1841 if (error) {
1842 filemap_remove_folio(folio);
1843 goto unlock;
1844 }
1845 }
1846
1847 shmem_recalc_inode(inode, pages, 0);
1848 folio_add_lru(folio);
1849 return folio;
1850
1851 unlock:
1852 folio_unlock(folio);
1853 folio_put(folio);
1854 return ERR_PTR(error);
1855 }
1856
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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