On Sat, Oct 10, 2020 at 3:39 AM Muchun Song [off-list ref] wrote:

The amount of memory allocated to sockets buffer can become significant.
However, we do not display the amount of memory consumed by sockets
buffer. In this case, knowing where the memory is consumed by the kernel

We do it via `ss -m`. Is it not sufficient? And if not, why not adding it there
rather than /proc/meminfo?

 static inline void __skb_frag_unref(skb_frag_t *frag)
 {
-       put_page(skb_frag_page(frag));
+       struct page *page = skb_frag_page(frag);
+
+       if (put_page_testzero(page)) {
+               dec_sock_node_page_state(page);
+               __put_page(page);
+       }
 }

You mix socket page frag with skb frag at least, not sure this is exactly
what you want, because clearly skb page frags are frequently used
by network drivers rather than sockets.

Also, which one matches this dec_sock_node_page_state()? Clearly
not skb_fill_page_desc() or __skb_frag_ref().

Thanks.