Re: [PATCH -mm -V3 03/21] mm, THP, swap: Support PMD swap mapping in swap_duplicate()

From: Huang\, Ying
Date: Tue Jun 12 2018 - 21:27:03 EST


Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> writes:

> On Tue, Jun 12, 2018 at 09:23:19AM +0800, Huang, Ying wrote:
>> Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> writes:
>> >> +#else
>> >> +static inline int __swap_duplicate_cluster(swp_entry_t *entry,
>> >
>> > This doesn't need inline.
>>
>> Why not? This is just a one line stub.
>
> Forgot to respond to this. The compiler will likely choose to optimize out
> calls to an empty function like this. Checking, this is indeed what it does in
> this case on my machine, with or without inline.

Yes. I believe a decent compiler will inline the function in any way.
And it does no harm to keep "inline" too, Yes?

> By the way, when building without CONFIG_THP_SWAP, we get
>
> linux/mm/swapfile.c:933:13: warning: â__swap_free_clusterâ defined but not used [-Wunused-function]
> static void __swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> ^~~~~~~~~~~~~~~~~~~

Thanks! I will fix this. Don't know why 0-Day didn't catch this.

Best Regards,
Huang, Ying