On Fri, 2024-02-02 at 10:10 +0800, Yunsheng Lin wrote:

On 2024/2/1 21:16, Paolo Abeni wrote:

quoted

from the __page_frag_cache_refill() allocator - which never accesses
the memory reserves.

I am not really sure I understand the above commemt.
The semantic is the same as skb_page_frag_refill() as explained above
as my understanding. Note that __page_frag_cache_refill() use 'gfp_mask'
for allocating order 3 pages and use the original 'gfp' for allocating
order 0 pages.

You are right! I got fooled misreading 'gfp' as 'gfp_mask' in there.

quoted

I'm unsure we want to propagate the __page_frag_cache_refill behavior
here, the current behavior could be required by some systems.

It looks like this series still leave the skb_page_frag_refill()
allocator alone, what about dropping this chunk, too? 

As explained above, I would prefer to keep it as it is as it seems
to be quite obvious that we can avoid possible pressure for mm by
not using memory reserve for order 3 pages as we have the fallback
for order 0 pages.

Please let me know if there is anything obvious I missed.

I still think/fear that behaviours changes here could have
subtle/negative side effects - even if I agree the change looks safe.

I think the series without this patch would still achieve its goals and
would be much more uncontroversial. What about move this patch as a
standalone follow-up?

Thanks!

Paolo