From: Anshuman Khandual <anshuman.khandual@arm.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
linux-mm@kvack.org, akpm@linux-foundation.org
Cc: linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
Christophe Leroy <christophe.leroy@c-s.fr>,
x86@kernel.org, Mike Rapoport <rppt@linux.ibm.com>,
Qian Cai <cai@lca.pw>,
Gerald Schaefer <gerald.schaefer@de.ibm.com>,
Vineet Gupta <vgupta@synopsys.com>,
linux-snps-arc@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 10/13] mm/debug_vm_pgtable/locks: Take correct page table lock
Date: Tue, 1 Sep 2020 09:14:37 +0530 [thread overview]
Message-ID: <7da0de4c-8fc8-7e40-c9f7-a8f2d875e364@arm.com> (raw)
In-Reply-To: <20200827080438.315345-11-aneesh.kumar@linux.ibm.com>
On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote:
> Make sure we call pte accessors with correct lock held.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
> mm/debug_vm_pgtable.c | 34 ++++++++++++++++++++--------------
> 1 file changed, 20 insertions(+), 14 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 78c8af3445ac..0a6e771ebd13 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -1039,33 +1039,39 @@ static int __init debug_vm_pgtable(void)
> pmd_thp_tests(pmd_aligned, prot);
> pud_thp_tests(pud_aligned, prot);
>
> + hugetlb_basic_tests(pte_aligned, prot);
> +
This moved back again. As pointed out earlier, there will be a bisect
problem and so this patch must be folded back with the previous one.
> /*
> * Page table modifying tests
> */
> - pte_clear_tests(mm, ptep, vaddr);
> - pmd_clear_tests(mm, pmdp);
> - pud_clear_tests(mm, pudp);
> - p4d_clear_tests(mm, p4dp);
> - pgd_clear_tests(mm, pgdp);
>
> ptep = pte_alloc_map_lock(mm, pmdp, vaddr, &ptl);
> + pte_clear_tests(mm, ptep, vaddr);
> pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
> - pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
> - pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
> - hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
> -
> + pte_unmap_unlock(ptep, ptl);
>
> + ptl = pmd_lock(mm, pmdp);
> + pmd_clear_tests(mm, pmdp);
> + pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
> pmd_huge_tests(pmdp, pmd_aligned, prot);
> + pmd_populate_tests(mm, pmdp, saved_ptep);
> + spin_unlock(ptl);
> +
> + ptl = pud_lock(mm, pudp);
> + pud_clear_tests(mm, pudp);
> + pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
> pud_huge_tests(pudp, pud_aligned, prot);
> + pud_populate_tests(mm, pudp, saved_pmdp);
> + spin_unlock(ptl);
>
> - pte_unmap_unlock(ptep, ptl);
> + hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
>
> - pmd_populate_tests(mm, pmdp, saved_ptep);
> - pud_populate_tests(mm, pudp, saved_pmdp);
> + spin_lock(&mm->page_table_lock);
> + p4d_clear_tests(mm, p4dp);
> + pgd_clear_tests(mm, pgdp);
> p4d_populate_tests(mm, p4dp, saved_pudp);
> pgd_populate_tests(mm, pgdp, saved_p4dp);
> -
> - hugetlb_basic_tests(pte_aligned, prot);
> + spin_unlock(&mm->page_table_lock);
>
> p4d_free(mm, saved_p4dp);
> pud_free(mm, saved_pudp);
>
Overall, grouping together dynamic tests at various page table levels and
taking a corresponding lock, makes sense. Commit message for the resultant
patch should include (a) Test classification (b) Grouping by function for
the static tests, by page table level for the dynamic tests (c) Locking
requirement for the dynamic tests each level etc.
next prev parent reply other threads:[~2020-09-01 3:47 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-27 8:04 [PATCH v3 00/13] mm/debug_vm_pgtable fixes Aneesh Kumar K.V
2020-08-27 8:04 ` [PATCH v3 01/13] powerpc/mm: Add DEBUG_VM WARN for pmd_clear Aneesh Kumar K.V
2020-09-01 3:12 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 02/13] powerpc/mm: Move setting pte specific flags to pfn_pte Aneesh Kumar K.V
2020-09-01 3:13 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value Aneesh Kumar K.V
2020-09-01 3:15 ` Anshuman Khandual
2020-09-01 6:21 ` Aneesh Kumar K.V
2020-09-01 7:32 ` Anshuman Khandual
2020-09-01 7:36 ` Aneesh Kumar K.V
2020-09-01 7:46 ` Anshuman Khandual
2020-09-01 7:55 ` Aneesh Kumar K.V
2020-09-02 3:45 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 04/13] mm/debug_vm_pgtables/hugevmap: Use the arch helper to identify huge vmap support Aneesh Kumar K.V
2020-09-01 3:16 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 05/13] mm/debug_vm_pgtable/savedwrite: Enable savedwrite test with CONFIG_NUMA_BALANCING Aneesh Kumar K.V
2020-09-01 3:18 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 06/13] mm/debug_vm_pgtable/THP: Mark the pte entry huge before using set_pmd/pud_at Aneesh Kumar K.V
2020-09-01 3:21 ` Anshuman Khandual
2020-09-01 6:23 ` Aneesh Kumar K.V
2020-08-27 8:04 ` [PATCH v3 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry Aneesh Kumar K.V
2020-08-27 8:04 ` [PATCH v3 08/13] mm/debug_vm_pgtable/thp: Use page table depost/withdraw with THP Aneesh Kumar K.V
2020-09-01 3:22 ` Anshuman Khandual
2020-09-01 6:25 ` Aneesh Kumar K.V
2020-09-01 6:50 ` Christophe Leroy
2020-09-01 7:40 ` Aneesh Kumar K.V
2020-09-01 7:51 ` Christophe Leroy
2020-09-02 3:45 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 09/13] mm/debug_vm_pgtable/locks: Move non page table modifying test together Aneesh Kumar K.V
2020-09-01 3:41 ` Anshuman Khandual
2020-09-01 6:38 ` Aneesh Kumar K.V
2020-09-01 9:33 ` Anshuman Khandual
2020-09-01 9:36 ` Aneesh Kumar K.V
2020-09-01 9:58 ` Anshuman Khandual
2020-08-27 8:04 ` [PATCH v3 10/13] mm/debug_vm_pgtable/locks: Take correct page table lock Aneesh Kumar K.V
2020-09-01 3:44 ` Anshuman Khandual [this message]
2020-08-27 8:04 ` [PATCH v3 11/13] mm/debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries Aneesh Kumar K.V
2020-08-27 8:04 ` [PATCH v3 12/13] mm/debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64 Aneesh Kumar K.V
2020-09-01 4:03 ` Anshuman Khandual
2020-09-01 6:30 ` Aneesh Kumar K.V
2020-09-01 7:59 ` Christophe Leroy
2020-09-02 13:05 ` Anshuman Khandual
2020-09-02 13:20 ` Aneesh Kumar K.V
2020-08-27 8:04 ` [PATCH v3 13/13] mm/debug_vm_pgtable: populate a pte entry before fetching it Aneesh Kumar K.V
2020-08-27 12:17 ` kernel test robot
2020-09-01 3:25 ` Anshuman Khandual
2020-09-01 6:37 ` Aneesh Kumar K.V
2020-09-01 7:38 ` Anshuman Khandual
2020-09-01 9:58 ` Aneesh Kumar K.V
2020-09-02 3:49 ` Anshuman Khandual
2020-09-02 3:58 ` Aneesh Kumar K.V
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