Re: [PATCH] mm: multi-gen LRU: Optimize some duplicate codes

From: kernel test robot
Date: Fri Aug 25 2023 - 01:29:39 EST

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In reply to: Xin Hao: "[PATCH] mm: multi-gen LRU: Optimize some duplicate codes"
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Hi Xin,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]

url: https://github.com/intel-lab-lkp/linux/commits/Xin-Hao/mm-multi-gen-LRU-Optimize-some-duplicate-codes/20230824-193855
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230824113538.5160-1-user%40VERNHAO-MC1
patch subject: [PATCH] mm: multi-gen LRU: Optimize some duplicate codes
config: openrisc-randconfig-r025-20230825 (https://download.01.org/0day-ci/archive/20230825/202308251315.UUQoJwKC-lkp@xxxxxxxxx/config)
compiler: or1k-linux-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230825/202308251315.UUQoJwKC-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308251315.UUQoJwKC-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

mm/vmscan.c: In function 'lru_gen_look_around':
>> mm/vmscan.c:4681:14: warning: unused variable 'can_swap' [-Wunused-variable]
4681 | bool can_swap = !folio_is_file_lru(folio);
| ^~~~~~~~

vim +/can_swap +4681 mm/vmscan.c

ac35a490237446 Yu Zhao 2022-09-18 4659
db19a43d9b3a88 T.J. Alumbaugh 2023-01-18 4660 /******************************************************************************
db19a43d9b3a88 T.J. Alumbaugh 2023-01-18 4661 * rmap/PT walk feedback
db19a43d9b3a88 T.J. Alumbaugh 2023-01-18 4662 ******************************************************************************/
db19a43d9b3a88 T.J. Alumbaugh 2023-01-18 4663
018ee47f14893d Yu Zhao 2022-09-18 4664 /*
49fd9b6df54e61 Matthew Wilcox (Oracle 2022-09-02 4665) * This function exploits spatial locality when shrink_folio_list() walks the
bd74fdaea14602 Yu Zhao 2022-09-18 4666 * rmap. It scans the adjacent PTEs of a young PTE and promotes hot pages. If
bd74fdaea14602 Yu Zhao 2022-09-18 4667 * the scan was done cacheline efficiently, it adds the PMD entry pointing to
bd74fdaea14602 Yu Zhao 2022-09-18 4668 * the PTE table to the Bloom filter. This forms a feedback loop between the
bd74fdaea14602 Yu Zhao 2022-09-18 4669 * eviction and the aging.
018ee47f14893d Yu Zhao 2022-09-18 4670 */
018ee47f14893d Yu Zhao 2022-09-18 4671 void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
018ee47f14893d Yu Zhao 2022-09-18 4672 {
018ee47f14893d Yu Zhao 2022-09-18 4673 int i;
018ee47f14893d Yu Zhao 2022-09-18 4674 unsigned long start;
018ee47f14893d Yu Zhao 2022-09-18 4675 unsigned long end;
bd74fdaea14602 Yu Zhao 2022-09-18 4676 struct lru_gen_mm_walk *walk;
bd74fdaea14602 Yu Zhao 2022-09-18 4677 int young = 0;
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4678 pte_t *pte = pvmw->pte;
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4679 unsigned long addr = pvmw->address;
018ee47f14893d Yu Zhao 2022-09-18 4680 struct folio *folio = pfn_folio(pvmw->pfn);
a3235ea2a88b78 Kalesh Singh 2023-08-01 @4681 bool can_swap = !folio_is_file_lru(folio);
018ee47f14893d Yu Zhao 2022-09-18 4682 struct mem_cgroup *memcg = folio_memcg(folio);
018ee47f14893d Yu Zhao 2022-09-18 4683 struct pglist_data *pgdat = folio_pgdat(folio);
018ee47f14893d Yu Zhao 2022-09-18 4684 struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat);
018ee47f14893d Yu Zhao 2022-09-18 4685 DEFINE_MAX_SEQ(lruvec);
5eaa8481da76b4 Vern Hao 2023-08-24 4686 int new_gen = lru_gen_from_seq(max_seq);
5eaa8481da76b4 Vern Hao 2023-08-24 4687 int old_count = 0;
018ee47f14893d Yu Zhao 2022-09-18 4688
018ee47f14893d Yu Zhao 2022-09-18 4689 lockdep_assert_held(pvmw->ptl);
018ee47f14893d Yu Zhao 2022-09-18 4690 VM_WARN_ON_ONCE_FOLIO(folio_test_lru(folio), folio);
018ee47f14893d Yu Zhao 2022-09-18 4691
018ee47f14893d Yu Zhao 2022-09-18 4692 if (spin_is_contended(pvmw->ptl))
018ee47f14893d Yu Zhao 2022-09-18 4693 return;
018ee47f14893d Yu Zhao 2022-09-18 4694
bd74fdaea14602 Yu Zhao 2022-09-18 4695 /* avoid taking the LRU lock under the PTL when possible */
bd74fdaea14602 Yu Zhao 2022-09-18 4696 walk = current->reclaim_state ? current->reclaim_state->mm_walk : NULL;
bd74fdaea14602 Yu Zhao 2022-09-18 4697
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4698 start = max(addr & PMD_MASK, pvmw->vma->vm_start);
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4699 end = min(addr | ~PMD_MASK, pvmw->vma->vm_end - 1) + 1;
018ee47f14893d Yu Zhao 2022-09-18 4700
018ee47f14893d Yu Zhao 2022-09-18 4701 if (end - start > MIN_LRU_BATCH * PAGE_SIZE) {
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4702 if (addr - start < MIN_LRU_BATCH * PAGE_SIZE / 2)
018ee47f14893d Yu Zhao 2022-09-18 4703 end = start + MIN_LRU_BATCH * PAGE_SIZE;
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4704 else if (end - addr < MIN_LRU_BATCH * PAGE_SIZE / 2)
018ee47f14893d Yu Zhao 2022-09-18 4705 start = end - MIN_LRU_BATCH * PAGE_SIZE;
018ee47f14893d Yu Zhao 2022-09-18 4706 else {
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4707 start = addr - MIN_LRU_BATCH * PAGE_SIZE / 2;
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4708 end = addr + MIN_LRU_BATCH * PAGE_SIZE / 2;
018ee47f14893d Yu Zhao 2022-09-18 4709 }
018ee47f14893d Yu Zhao 2022-09-18 4710 }
018ee47f14893d Yu Zhao 2022-09-18 4711
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4712 /* folio_update_gen() requires stable folio_memcg() */
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4713 if (!mem_cgroup_trylock_pages(memcg))
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4714 return;
018ee47f14893d Yu Zhao 2022-09-18 4715
018ee47f14893d Yu Zhao 2022-09-18 4716 arch_enter_lazy_mmu_mode();
018ee47f14893d Yu Zhao 2022-09-18 4717
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4718 pte -= (addr - start) / PAGE_SIZE;
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4719
018ee47f14893d Yu Zhao 2022-09-18 4720 for (i = 0, addr = start; addr != end; i++, addr += PAGE_SIZE) {
5eaa8481da76b4 Vern Hao 2023-08-24 4721 if (!lru_gen_folio_status_check(pte + i, pvmw->vma, pgdat,
5eaa8481da76b4 Vern Hao 2023-08-24 4722 addr, new_gen, &old_count, walk, memcg))
018ee47f14893d Yu Zhao 2022-09-18 4723 continue;
bd74fdaea14602 Yu Zhao 2022-09-18 4724 young++;
018ee47f14893d Yu Zhao 2022-09-18 4725 }
018ee47f14893d Yu Zhao 2022-09-18 4726
018ee47f14893d Yu Zhao 2022-09-18 4727 arch_leave_lazy_mmu_mode();
abf086721a2f1e T.J. Alumbaugh 2023-01-18 4728 mem_cgroup_unlock_pages();
018ee47f14893d Yu Zhao 2022-09-18 4729
bd74fdaea14602 Yu Zhao 2022-09-18 4730 /* feedback from rmap walkers to page table walkers */
bd74fdaea14602 Yu Zhao 2022-09-18 4731 if (suitable_to_scan(i, young))
bd74fdaea14602 Yu Zhao 2022-09-18 4732 update_bloom_filter(lruvec, max_seq, pvmw->pmd);
018ee47f14893d Yu Zhao 2022-09-18 4733 }
018ee47f14893d Yu Zhao 2022-09-18 4734

--
0-DAY CI Kernel Test Service
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Next message: kernel test robot: "Re: [PATCH v14.b 7/7] ACPI: x86: s2idle: Add a function to get constraints for a device"
Previous message: Kees Cook: "[PATCH] hardening: Provide Kconfig fragments for basic options"
In reply to: Xin Hao: "[PATCH] mm: multi-gen LRU: Optimize some duplicate codes"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]