* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 11:25 ` [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Steve Capper
@ 2022-03-30 12:05 ` David Hildenbrand
2022-03-30 14:04 ` Anshuman Khandual
` (4 subsequent siblings)
5 siblings, 0 replies; 14+ messages in thread
From: David Hildenbrand @ 2022-03-30 12:05 UTC (permalink / raw)
To: Steve Capper, linux-mm
Cc: Peter Zijlstra, Anshuman Khandual, Catalin Marinas, Will Deacon
On 30.03.22 13:25, Steve Capper wrote:
> tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
> updating the mmu_gather structure.
>
> Unfortunately on arm64 there are two additional huge page sizes that
> need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
> attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
> due to the fact that the tlb structure hasn't been correctly updated by
> the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.
>
> This patch adds inequality logic to the generic implementation of
> tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are
> effectively covered on arm64. Also, as well as ptes, pmds and puds;
> p4ds are now considered too.
>
> Reported-by: David Hildenbrand <david@redhat.com>
> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/
> Signed-off-by: Steve Capper <steve.capper@arm.com>
>
> ---
>
> Changed in V2: instead of doing the per-arch implementation of
> tlb_remove_huge_tlb_entry we add to the generic implmentation, as
> suggested by PeterZ.
>
> This works well on arm64 with contiguous PTEs/PMDs. Does this look
> reasonable to the ppc folk?
>
> Cheers,
> --
> Steve
> ---
> include/asm-generic/tlb.h | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 2c68a545ffa7..71942a1c642d 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -565,10 +565,14 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
> #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
> do { \
> unsigned long _sz = huge_page_size(h); \
> - if (_sz == PMD_SIZE) \
> - tlb_flush_pmd_range(tlb, address, _sz); \
> - else if (_sz == PUD_SIZE) \
> + if (_sz >= P4D_SIZE) \
> + tlb_flush_p4d_range(tlb, address, _sz); \
> + else if (_sz >= PUD_SIZE) \
> tlb_flush_pud_range(tlb, address, _sz); \
> + else if (_sz >= PMD_SIZE) \
> + tlb_flush_pmd_range(tlb, address, _sz); \
> + else \
> + tlb_flush_pte_range(tlb, address, _sz); \
> __tlb_remove_tlb_entry(tlb, ptep, address); \
> } while (0)
>
LGTM
Acked-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 11:25 ` [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Steve Capper
2022-03-30 12:05 ` David Hildenbrand
@ 2022-03-30 14:04 ` Anshuman Khandual
2022-04-06 11:21 ` Peter Zijlstra
2022-04-04 6:07 ` Anshuman Khandual
` (3 subsequent siblings)
5 siblings, 1 reply; 14+ messages in thread
From: Anshuman Khandual @ 2022-03-30 14:04 UTC (permalink / raw)
To: Steve Capper, linux-mm
Cc: David Hildenbrand, Peter Zijlstra, Catalin Marinas, Will Deacon
On 3/30/22 16:55, Steve Capper wrote:
> tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
> updating the mmu_gather structure.
>
> Unfortunately on arm64 there are two additional huge page sizes that
> need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
> attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
> due to the fact that the tlb structure hasn't been correctly updated by
> the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.
>
> This patch adds inequality logic to the generic implementation of
> tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are
> effectively covered on arm64. Also, as well as ptes, pmds and puds;
> p4ds are now considered too.
>
> Reported-by: David Hildenbrand <david@redhat.com>
> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/
> Signed-off-by: Steve Capper <steve.capper@arm.com>
>
> ---
>
> Changed in V2: instead of doing the per-arch implementation of
> tlb_remove_huge_tlb_entry we add to the generic implmentation, as
> suggested by PeterZ.
>
> This works well on arm64 with contiguous PTEs/PMDs. Does this look
> reasonable to the ppc folk?
I am wondering whether this should take care of gigantic PGDIR_SIZE
based HugeTLB pages as well ? Although, it will require another new
helper tlb_flush_pgd_range(). Any thoughts ?
>
> Cheers,
> --
> Steve
> ---
> include/asm-generic/tlb.h | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 2c68a545ffa7..71942a1c642d 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -565,10 +565,14 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
> #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
> do { \
> unsigned long _sz = huge_page_size(h); \
> - if (_sz == PMD_SIZE) \
> - tlb_flush_pmd_range(tlb, address, _sz); \
> - else if (_sz == PUD_SIZE) \
> + if (_sz >= P4D_SIZE) \
> + tlb_flush_p4d_range(tlb, address, _sz); \
> + else if (_sz >= PUD_SIZE) \
> tlb_flush_pud_range(tlb, address, _sz); \
> + else if (_sz >= PMD_SIZE) \
> + tlb_flush_pmd_range(tlb, address, _sz); \
> + else \
> + tlb_flush_pte_range(tlb, address, _sz); \
> __tlb_remove_tlb_entry(tlb, ptep, address); \
> } while (0)
>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 14:04 ` Anshuman Khandual
@ 2022-04-06 11:21 ` Peter Zijlstra
0 siblings, 0 replies; 14+ messages in thread
From: Peter Zijlstra @ 2022-04-06 11:21 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Steve Capper, linux-mm, David Hildenbrand, Catalin Marinas, Will Deacon
On Wed, Mar 30, 2022 at 07:34:16PM +0530, Anshuman Khandual wrote:
> I am wondering whether this should take care of gigantic PGDIR_SIZE
> based HugeTLB pages as well ? Although, it will require another new
> helper tlb_flush_pgd_range(). Any thoughts ?
I'm thinking that should be straight forward, you need a ->cleared_pgds
along with all that, but yeah.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 11:25 ` [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Steve Capper
2022-03-30 12:05 ` David Hildenbrand
2022-03-30 14:04 ` Anshuman Khandual
@ 2022-04-04 6:07 ` Anshuman Khandual
2022-04-05 14:26 ` Catalin Marinas
` (2 subsequent siblings)
5 siblings, 0 replies; 14+ messages in thread
From: Anshuman Khandual @ 2022-04-04 6:07 UTC (permalink / raw)
To: Steve Capper, linux-mm
Cc: David Hildenbrand, Peter Zijlstra, Catalin Marinas, Will Deacon
On 3/30/22 16:55, Steve Capper wrote:
> tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
> updating the mmu_gather structure.
>
> Unfortunately on arm64 there are two additional huge page sizes that
> need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
> attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
> due to the fact that the tlb structure hasn't been correctly updated by
> the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.
>
> This patch adds inequality logic to the generic implementation of
> tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are
> effectively covered on arm64. Also, as well as ptes, pmds and puds;
> p4ds are now considered too.
>
> Reported-by: David Hildenbrand <david@redhat.com>
> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/
> Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
>
> ---
>
> Changed in V2: instead of doing the per-arch implementation of
> tlb_remove_huge_tlb_entry we add to the generic implmentation, as
> suggested by PeterZ.
>
> This works well on arm64 with contiguous PTEs/PMDs. Does this look
> reasonable to the ppc folk?
>
> Cheers,
> --
> Steve
> ---
> include/asm-generic/tlb.h | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 2c68a545ffa7..71942a1c642d 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -565,10 +565,14 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
> #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
> do { \
> unsigned long _sz = huge_page_size(h); \
> - if (_sz == PMD_SIZE) \
> - tlb_flush_pmd_range(tlb, address, _sz); \
> - else if (_sz == PUD_SIZE) \
> + if (_sz >= P4D_SIZE) \
> + tlb_flush_p4d_range(tlb, address, _sz); \
> + else if (_sz >= PUD_SIZE) \
> tlb_flush_pud_range(tlb, address, _sz); \
> + else if (_sz >= PMD_SIZE) \
> + tlb_flush_pmd_range(tlb, address, _sz); \
> + else \
> + tlb_flush_pte_range(tlb, address, _sz); \
> __tlb_remove_tlb_entry(tlb, ptep, address); \
> } while (0)
>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 11:25 ` [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Steve Capper
` (2 preceding siblings ...)
2022-04-04 6:07 ` Anshuman Khandual
@ 2022-04-05 14:26 ` Catalin Marinas
2022-04-06 11:40 ` Peter Zijlstra
2022-04-06 12:05 ` Will Deacon
5 siblings, 0 replies; 14+ messages in thread
From: Catalin Marinas @ 2022-04-05 14:26 UTC (permalink / raw)
To: Steve Capper
Cc: linux-mm, David Hildenbrand, Peter Zijlstra, Anshuman Khandual,
Will Deacon
On Wed, Mar 30, 2022 at 12:25:43PM +0100, Steve Capper wrote:
> tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
> updating the mmu_gather structure.
>
> Unfortunately on arm64 there are two additional huge page sizes that
> need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
> attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
> due to the fact that the tlb structure hasn't been correctly updated by
> the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.
>
> This patch adds inequality logic to the generic implementation of
> tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are
> effectively covered on arm64. Also, as well as ptes, pmds and puds;
> p4ds are now considered too.
>
> Reported-by: David Hildenbrand <david@redhat.com>
> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/
> Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 11:25 ` [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Steve Capper
` (3 preceding siblings ...)
2022-04-05 14:26 ` Catalin Marinas
@ 2022-04-06 11:40 ` Peter Zijlstra
2022-04-06 12:05 ` Will Deacon
5 siblings, 0 replies; 14+ messages in thread
From: Peter Zijlstra @ 2022-04-06 11:40 UTC (permalink / raw)
To: Steve Capper
Cc: linux-mm, David Hildenbrand, Anshuman Khandual, Catalin Marinas,
Will Deacon
On Wed, Mar 30, 2022 at 12:25:43PM +0100, Steve Capper wrote:
> tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
> updating the mmu_gather structure.
>
> Unfortunately on arm64 there are two additional huge page sizes that
> need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
> attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
> due to the fact that the tlb structure hasn't been correctly updated by
> the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.
>
> This patch adds inequality logic to the generic implementation of
> tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are
> effectively covered on arm64. Also, as well as ptes, pmds and puds;
> p4ds are now considered too.
>
> Reported-by: David Hildenbrand <david@redhat.com>
> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/
> Signed-off-by: Steve Capper <steve.capper@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> include/asm-generic/tlb.h | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 2c68a545ffa7..71942a1c642d 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -565,10 +565,14 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
> #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
> do { \
> unsigned long _sz = huge_page_size(h); \
> - if (_sz == PMD_SIZE) \
> - tlb_flush_pmd_range(tlb, address, _sz); \
> - else if (_sz == PUD_SIZE) \
> + if (_sz >= P4D_SIZE) \
> + tlb_flush_p4d_range(tlb, address, _sz); \
> + else if (_sz >= PUD_SIZE) \
> tlb_flush_pud_range(tlb, address, _sz); \
> + else if (_sz >= PMD_SIZE) \
> + tlb_flush_pmd_range(tlb, address, _sz); \
> + else \
> + tlb_flush_pte_range(tlb, address, _sz); \
> __tlb_remove_tlb_entry(tlb, ptep, address); \
> } while (0)
>
> --
> 2.35.1
>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
2022-03-30 11:25 ` [PATCH v2] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Steve Capper
` (4 preceding siblings ...)
2022-04-06 11:40 ` Peter Zijlstra
@ 2022-04-06 12:05 ` Will Deacon
5 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2022-04-06 12:05 UTC (permalink / raw)
To: linux-mm, Steve Capper
Cc: catalin.marinas, kernel-team, Will Deacon, Anshuman Khandual,
David Hildenbrand, Peter Zijlstra
On Wed, 30 Mar 2022 12:25:43 +0100, Steve Capper wrote:
> tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
> updating the mmu_gather structure.
>
> Unfortunately on arm64 there are two additional huge page sizes that
> need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
> attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
> due to the fact that the tlb structure hasn't been correctly updated by
> the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.
>
> [...]
Applied to arm64 (for-next/fixes), thanks!
[1/1] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
https://git.kernel.org/arm64/c/697a1d44af8b
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
^ permalink raw reply [flat|nested] 14+ messages in thread