From: Peter Xu <peterx@redhat.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nathan Chancellor <nathan@kernel.org>,
linux-mm@kvack.org, akpm@linux-foundation.org,
mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
kaleshsingh@google.com, npiggin@gmail.com,
joel@joelfernandes.org,
Christophe Leroy <christophe.leroy@csgroup.eu>
Subject: Re: [PATCH v5 3/9] mm/mremap: Use pmd/pud_poplulate to update page table entries
Date: Wed, 19 May 2021 22:18:43 -0400 [thread overview]
Message-ID: <YKXHA8/HmP6HXngO@t490s> (raw)
In-Reply-To: <87mtsrqqk0.fsf@linux.ibm.com>
On Wed, May 19, 2021 at 10:16:07AM +0530, Aneesh Kumar K.V wrote:
> > On Thu, Apr 22, 2021 at 11:13:17AM +0530, Aneesh Kumar K.V wrote:
> >> pmd/pud_populate is the right interface to be used to set the respective
> >> page table entries. Some architectures like ppc64 do assume that set_pmd/pud_at
> >> can only be used to set a hugepage PTE. Since we are not setting up a hugepage
> >> PTE here, use the pmd/pud_populate interface.
[1]
> Can you try this change?
>
> modified mm/mremap.c
> @@ -279,7 +279,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
> pmd_clear(old_pmd);
>
> VM_BUG_ON(!pmd_none(*new_pmd));
> - pmd_populate(mm, new_pmd, (pgtable_t)pmd_page_vaddr(pmd));
> + pmd_populate(mm, new_pmd, pmd_pgtable(pmd));
>
> if (new_ptl != old_ptl)
> spin_unlock(new_ptl);
I reported this issue today somewhere else:
https://lore.kernel.org/linux-mm/YKVemB5DuSqLFmmz@t490s/
And came to this same line after the bisection.
This seems to work at least for my userfaultfd test on shmem, however I don't
fully understand the commit message [1] on: How do we guarantee we're not
moving a thp pte?
--
Peter Xu
next prev parent reply other threads:[~2021-05-20 2:18 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 5:43 [PATCH v5 0/9] Speedup mremap on ppc64 Aneesh Kumar K.V
2021-04-22 5:43 ` [PATCH v5 1/9] selftest/mremap_test: Update the test to handle pagesize other than 4K Aneesh Kumar K.V
2021-04-22 5:43 ` [PATCH v5 2/9] selftest/mremap_test: Avoid crash with static build Aneesh Kumar K.V
2021-04-22 5:43 ` [PATCH v5 3/9] mm/mremap: Use pmd/pud_poplulate to update page table entries Aneesh Kumar K.V
2021-05-18 20:04 ` Nathan Chancellor
2021-05-19 4:46 ` Aneesh Kumar K.V
2021-05-19 18:02 ` Nathan Chancellor
2021-05-20 2:18 ` Peter Xu [this message]
2021-05-20 8:26 ` Aneesh Kumar K.V
2021-05-20 12:46 ` Peter Xu
2021-05-20 13:23 ` Aneesh Kumar K.V
2021-05-20 13:37 ` Aneesh Kumar K.V
2021-05-20 14:57 ` Peter Xu
2021-05-20 19:06 ` Zi Yan
2021-05-20 20:01 ` Peter Xu
2021-05-20 20:25 ` Kalesh Singh
2021-04-22 5:43 ` [PATCH v5 4/9] powerpc/mm/book3s64: Fix possible build error Aneesh Kumar K.V
2021-04-22 5:43 ` [PATCH v5 5/9] powerpc/mm/book3s64: Update tlb flush routines to take a page walk cache flush argument Aneesh Kumar K.V
2021-05-15 16:35 ` Guenter Roeck
2021-05-15 20:41 ` Andrew Morton
2021-05-15 23:05 ` Guenter Roeck
2021-05-17 8:40 ` Aneesh Kumar K.V
2021-05-17 13:38 ` Guenter Roeck
2021-05-17 13:55 ` Aneesh Kumar K.V
2021-05-17 14:18 ` Guenter Roeck
2021-05-19 0:26 ` Michael Ellerman
2021-05-19 0:45 ` Segher Boessenkool
2021-05-19 12:03 ` Segher Boessenkool
2021-05-19 13:37 ` Guenter Roeck
2021-05-19 14:20 ` Segher Boessenkool
2021-05-19 15:28 ` Guenter Roeck
2021-05-20 7:37 ` Michael Ellerman
2021-05-20 12:17 ` Segher Boessenkool
2021-05-19 1:08 ` Guenter Roeck
2021-05-20 11:38 ` Michael Ellerman
2021-05-20 11:56 ` Guenter Roeck
2021-04-22 5:43 ` [PATCH v5 6/9] mm/mremap: Use range flush that does TLB and page walk cache flush Aneesh Kumar K.V
2021-04-22 5:43 ` [PATCH v5 7/9] mm/mremap: Move TLB flush outside page table lock Aneesh Kumar K.V
2021-05-20 15:26 ` Aneesh Kumar K.V
2021-05-20 16:57 ` Aneesh Kumar K.V
2021-05-21 2:40 ` Linus Torvalds
2021-05-21 3:03 ` Aneesh Kumar K.V
2021-05-21 3:28 ` Aneesh Kumar K.V
2021-05-21 6:13 ` Linus Torvalds
2021-05-21 12:50 ` Aneesh Kumar K.V
2021-05-21 13:03 ` Aneesh Kumar K.V
2021-05-21 16:03 ` Linus Torvalds
2021-05-21 16:29 ` Aneesh Kumar K.V
2021-05-24 14:24 ` Aneesh Kumar K.V
2021-05-21 15:24 ` Liam Howlett
2021-05-21 16:02 ` Aneesh Kumar K.V
2021-05-21 16:05 ` Linus Torvalds
2021-04-22 5:43 ` [PATCH v5 8/9] mm/mremap: Allow arch runtime override Aneesh Kumar K.V
2021-04-22 5:43 ` [PATCH v5 9/9] powerpc/mm: Enable move pmd/pud Aneesh Kumar K.V
2021-05-11 22:19 ` Andrew Morton
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