Re: [PATCH v3 4/7] proc/task_mmu: remove special-casing of smap_gather_stats() start parameter

[David Hildenbrand (Arm)]

On 9/11/26 01:47, Suren Baghdasaryan wrote:
> smap_gather_stats() interprets its start parameter to mean vma->vm_start
> when it's set to 0. Eliminate this special interpretation and pass
> vma->vm_start explicitly when needed.
> 
> Since smap_gather_stats() operates within a single VMA, we can replace
> walk_page_vma()/walk_page_range() calls with walk_page_range_vma()
> which is simpler and also can be called while holding per-VMA lock.
> 
> No functional change intended.
> 
> Suggested by: Lorenzo Stoakes <ljs@xxxxxxxxxx>
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> Reviewed-by: Liam R. Howlett (Oracle) <liam@xxxxxxxxxxxxx>
> ---
>  fs/proc/task_mmu.c | 29 ++++++++++++++++-------------
>  1 file changed, 16 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 3c40c9cbb9c9..ecce7ce116cb 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -1246,21 +1246,27 @@ get_smaps_shmem_walk_ops(struct proc_maps_private *priv)
>  	return &smaps_shmem_walk_vma_lock_ops;
>  }
>  
> -/*
> - * Gather mem stats from @vma with the indicated beginning
> - * address @start, and keep them in @mss.
> +/**
> + * smap_gather_stats() - Gather mem stats from @vma.
> + * @priv: proc maps private state.
> + * @vma: The VMA to gather stats for.
> + * @mss: The accumulated stats.
> + * @start: The address from which to start.
>   *
> - * Use vm_start of @vma as the beginning address if @start is 0.
> + * This gathers stats for the whole of the VMA unless the lock was dropped
> + * and VMA grew or got merged and we found it again, in which case we only
> + * gather stats for the remainder of the VMA range.
>   */
>  static void smap_gather_stats(struct proc_maps_private *priv,
>  			      struct vm_area_struct *vma,
> -			      struct mem_size_stats *mss, unsigned long start)
> +			      struct mem_size_stats *mss,
> +			      unsigned long start)

Two tabs while at it :P

Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

-- 
Cheers,

David