Re: [PATCH v3] mm: shmem: skip swapcache for swapin of synchronous swap device

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 2025/1/8 10:29, Andrew Morton wrote:
> On Wed,  8 Jan 2025 10:16:49 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote:
> 
>> +static struct folio *shmem_swap_alloc_folio(struct inode *inode,
>> +		struct vm_area_struct *vma, pgoff_t index,
>> +		swp_entry_t entry, int order, gfp_t gfp)
>> +{
>> +	struct shmem_inode_info *info = SHMEM_I(inode);
>> +	struct folio *new;
>> +	void *shadow;
>> +	int nr_pages;
>> +
>> +	/*
>> +	 * We have arrived here because our zones are constrained, so don't
>> +	 * limit chance of success by further cpuset and node constraints.
>> +	 */
>> +	gfp &= ~GFP_CONSTRAINT_MASK;
>> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> +	if (order > 0) {
>> +		gfp_t huge_gfp = vma_thp_gfp_mask(vma);
>> +
>> +		gfp = limit_gfp_mask(huge_gfp, gfp);
>> +	}
>> +#endif
>> +
> 
> Can we do this?
> 
> --- a/mm/shmem.c~mm-shmem-skip-swapcache-for-swapin-of-synchronous-swap-device-fix
> +++ a/mm/shmem.c
> @@ -1978,16 +1978,14 @@ static struct folio *shmem_swap_alloc_fo
>   
>   	/*
>   	 * We have arrived here because our zones are constrained, so don't
> -	 * limit chance of success by further cpuset and node constraints.
> +	 * limit chance of success with further cpuset and node constraints.
>   	 */
>   	gfp &= ~GFP_CONSTRAINT_MASK;
> -#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -	if (order > 0) {
> +	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && order > 0) {
>   		gfp_t huge_gfp = vma_thp_gfp_mask(vma);
>   
>   		gfp = limit_gfp_mask(huge_gfp, gfp);
>   	}
> -#endif
>   
>   	new = shmem_alloc_folio(gfp, order, info, index);
>   	if (!new)
> _

Yes, looks good to me. Thanks.