Re: [PATCH v5 7/9] mm/mmu_notifier: pass down vma and reasons why mmu notifier is happening v2

[Ralph Campbell <rcampbell@nvidia.com>]

On 2/19/19 12:04 PM, jglisse@redhat.com wrote:
> From: Jérôme Glisse <jglisse@redhat.com>
> 
> CPU page table update can happens for many reasons, not only as a result
> of a syscall (munmap(), mprotect(), mremap(), madvise(), ...) but also
> as a result of kernel activities (memory compression, reclaim, migration,
> ...).
> 
> Users of mmu notifier API track changes to the CPU page table and take
> specific action for them. While current API only provide range of virtual
> address affected by the change, not why the changes is happening
> 
> This patch is just passing down the new informations by adding it to the
> mmu_notifier_range structure.
> 
> Changes since v1:
>      - Initialize flags field from mmu_notifier_range_init() arguments
> 
> Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Andrea Arcangeli <aarcange@redhat.com>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Felix Kuehling <Felix.Kuehling@amd.com>
> Cc: Jason Gunthorpe <jgg@mellanox.com>
> Cc: Ross Zwisler <zwisler@kernel.org>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Christian Koenig <christian.koenig@amd.com>
> Cc: Ralph Campbell <rcampbell@nvidia.com>
> Cc: John Hubbard <jhubbard@nvidia.com>
> Cc: kvm@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-rdma@vger.kernel.org
> Cc: Arnd Bergmann <arnd@arndb.de>
> ---
>   include/linux/mmu_notifier.h | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 62f94cd85455..0379956fff23 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -58,10 +58,12 @@ struct mmu_notifier_mm {
>   #define MMU_NOTIFIER_RANGE_BLOCKABLE (1 << 0)
>   
>   struct mmu_notifier_range {
> +	struct vm_area_struct *vma;
>   	struct mm_struct *mm;
>   	unsigned long start;
>   	unsigned long end;
>   	unsigned flags;
> +	enum mmu_notifier_event event;
>   };
>   
>   struct mmu_notifier_ops {
> @@ -363,10 +365,12 @@ static inline void mmu_notifier_range_init(struct mmu_notifier_range *range,
>   					   unsigned long start,
>   					   unsigned long end)
>   {
> +	range->vma = vma;
> +	range->event = event;
>   	range->mm = mm;
>   	range->start = start;
>   	range->end = end;
> -	range->flags = 0;
> +	range->flags = flags;
>   }
>   
>   #define ptep_clear_flush_young_notify(__vma, __address, __ptep)		\
> 

Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>