Hi Arnaldo, On Fri, Apr 19, 2024 at 05:57:43PM -0300, Arnaldo Carvalho de Melo wrote: > Hi, > > Please take a look if you agree this is a more compact, less > confusing way of asking for the set of standard BTF features + some > extra features such as 'reproducible_build'. > > We have this in perf, for things like: > > ⬢[acme@toolbox pahole]$ perf report -h -F > > Usage: perf report [<options>] > > -F, --fields <key[,keys...]> > output field(s): overhead period sample overhead overhead_sys > overhead_us overhead_guest_sys overhead_guest_us overhead_children > sample period weight1 weight2 weight3 ins_lat retire_lat > p_stage_cyc pid comm dso symbol parent cpu socket > srcline srcfile local_weight weight transaction trace > symbol_size dso_size cgroup cgroup_id ipc_null time > code_page_size local_ins_lat ins_lat local_p_stage_cyc > p_stage_cyc addr local_retire_lat retire_lat simd > type typeoff symoff dso_from dso_to symbol_from symbol_to > mispredict abort in_tx cycles srcline_from srcline_to > ipc_lbr addr_from addr_to symbol_daddr dso_daddr locked > tlb mem snoop dcacheline symbol_iaddr phys_daddr data_page_size > blocked > > ⬢[acme@toolbox pahole]$ > > From the 'perf report' man page for '-F': > > If the keys starts with a prefix '+', then it will append the specified > field(s) to the default field order. For example: perf report -F +period,sample. I think for perf it makes sense to have compact representation b/c folks might be doing a lot of ad-hoc work. But encoding BTF seems more like a write-once, read mostly. So having `+` notation doesn't feel like it'd help that much. As someone who's not seen that style of syntax before, it's not immediately obvious what it does. But seeing `all`, I have a pretty good idea. [..] Thanks, Daniel
