Messages in this thread | | | Subject | Re: [PATCH v2 01/12] mm/debug_vm_pgtable: Introduce struct pgtable_debug_args | From | Anshuman Khandual <> | Date | Tue, 20 Jul 2021 12:12:35 +0530 |
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On 7/19/21 6:31 PM, Gavin Shan wrote: >> + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && >> + has_transparent_hugepage()) { >> + page = alloc_pages(GFP_KERNEL, HPAGE_PMD_ORDER); >> + if (page) { >> + args->pmd_pfn = page_to_pfn(page); >> + args->pte_pfn = args->pmd_pfn; >> + return 0; >> + } >> + } >> + > > As syzbot reported against v1 series, we could allocate pages larger than (1 << (MAX_ORDER - 1)) here. > So __GFP_NOWARN is needed here. I will fix it in v3 series.
I could find the following build error reported from lkp on V2.
mm/debug_vm_pgtable.c:445:8: warning: variable 'pud' set but not used [-Wunused-but-set-variable]
Could you please point to the syzbot reported problem on V1 as you have mentioned above. Are there configs where HPAGE_[PMD|PUD]_ORDER is greater than (MAX_ORDER - 1) ? If yes, how adding __GFP_NOWARN solves the problem ?
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