On 2023/11/8 5:19, Mina Almasry wrote: >> >> > > My personal immediate reaction is that this may just introduce code > churn without significant benefit. If an unsuspecting caller call > skb_frag_page() on devmem frag and doesn't correctly handle NULL > return, it will crash or error out anyway, and likely in some obvious > way, so maybe the BUG_ON() isn't so useful that it's worth changing If it will always crash or error out, then I agree that BUG_ON() is unnecessary. > all the call sites. But if there is consensus on adding a change like > you propose, I have no problem adding it. One obvious benefit I forget to mention is that, it provides a better semantic that if a caller need to do the return checking: 1. For the old helper, the semantic is not to do the checking if the caller has ensure that it has passed a readable frag to skb_frag_page(), which avoid adding some overhead for non-devmen supported drivers. 2. For the new helper, the semantic is to do the checking and we may provide a compiler '__must_check' function-attribute to ensure the caller to do the checking. >
