Re: [PATCH v2 1/3] mm/mmu_notifier: use structure for invalidate_range_start/end callback

[Jan Kara]

On Wed 05-12-18 00:36:26, jglisse@xxxxxxxxxx wrote:
> diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
> index 5119ff846769..5f6665ae3ee2 100644
> --- a/mm/mmu_notifier.c
> +++ b/mm/mmu_notifier.c
> @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
>  				  unsigned long start, unsigned long end,
>  				  bool blockable)
>  {
> +	struct mmu_notifier_range _range, *range = &_range;

Why these games with two variables?

>  	struct mmu_notifier *mn;
>  	int ret = 0;
>  	int id;
>  
> +	range->blockable = blockable;
> +	range->start = start;
> +	range->end = end;
> +	range->mm = mm;
> +

Use your init function for this?

>  	id = srcu_read_lock(&srcu);
>  	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
>  		if (mn->ops->invalidate_range_start) {
> -			int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable);
> +			int _ret = mn->ops->invalidate_range_start(mn, range);
>  			if (_ret) {
>  				pr_info("%pS callback failed with %d in %sblockable context.\n",
>  						mn->ops->invalidate_range_start, _ret,
> @@ -205,9 +211,20 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
>  					 unsigned long end,
>  					 bool only_end)
>  {
> +	struct mmu_notifier_range _range, *range = &_range;
>  	struct mmu_notifier *mn;
>  	int id;
>  
> +	/*
> +	 * The end call back will never be call if the start refused to go
> +	 * through because of blockable was false so here assume that we
> +	 * can block.
> +	 */
> +	range->blockable = true;
> +	range->start = start;
> +	range->end = end;
> +	range->mm = mm;
> +

The same as above.

Otherwise the patch looks good to me.

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR