Re: [PATCH v2 4/5] mm/madvise: thread all madvise state through madv_behavior

[SeongJae Park]

On Fri, 20 Jun 2025 16:33:04 +0100 Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> wrote:

> Doing so means we can get rid of all the weird struct vm_area_struct **prev
> stuff, everything becomes consistent and in future if we want to make
> change to behaviour there's a single place where all relevant state is
> stored.
> 
> This also allows us to update try_vma_read_lock() to be a little more
> succinct and set up state for us, as well as cleaning up
> madvise_update_vma().
> 
> We also update the debug assertion prior to madvise_update_vma() to assert
> that this is a write operation as correctly pointed out by Barry in the
> relevant thread.
> 
> We can't reasonably update the madvise functions that live outside of
> mm/madvise.c so we leave those as-is.
> 
> Acked-by: Zi Yan <ziy@xxxxxxxxxx>
> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>

Found a very trivial nit below.  Other than that,

Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>

[...]
> @@ -1607,23 +1615,19 @@ int madvise_walk_vmas(struct madvise_behavior *madv_behavior)
>  	struct madvise_behavior_range *range = &madv_behavior->range;
>  	/* range is updated to span each VMA, so store end of entire range. */
>  	unsigned long last_end = range->end;
> -	struct vm_area_struct *vma;
> -	struct vm_area_struct *prev;
>  	int unmapped_error = 0;
>  	int error;
> +	struct vm_area_struct *vma;

A very trivial nit.  We could just keep old 'struct vm_area_struct *vma'
declaration.


Thanks,
SJ

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