On Thu, 21 Sep 2023 10:51:30 +0200 Johannes Berg wrote: > So I was frustrated with not seeing the names of SKB dropreasons > for all but the core reasons, and then while looking into this > all, realized, that the current __print_symbolic() is pretty bad > anyway. > > So I came up with a new approach, using a separate declaration > of the symbols, and __print_sym() in there, but to userspace it > all doesn't matter, it shows it the same way, just dyamically > instead of munging with the strings all the time. > > This is a huge .data savings as far as I can tell, with a modest > amount (~4k) of .text addition, while making it all dynamic and > in the SKB dropreason case even reusing the existing list that > dropmonitor uses today. Surely patch 3 isn't needed here, but it > felt right. > > Anyway, I think it's a pretty reasonable approach overall, and > it does works. > > I've listed a number of open questions in the first patch since > that's where the real changes for this are. Potentially naive question - the trace point holds enum skb_drop_reason. The user space can get the names from BTF. Can we not teach user space to generically look up names of enums in BTF?
