Em Tue, Nov 10, 2020 at 01:22:32PM +0100, Peter Zijlstra escreveu: > On Tue, Nov 10, 2020 at 08:54:26AM -0300, Arnaldo Carvalho de Melo wrote: > > Em Tue, Nov 10, 2020 at 09:07:16AM +0100, Peter Zijlstra escreveu: > > > On Mon, Nov 09, 2020 at 10:53:54PM +0100, Jiri Olsa wrote: > > > > Adding support to carry build id data in mmap2 event.
> > > > The build id data replaces maj/min/ino/ino_generation > > > > fields, whichc are also used to identify map's binary, > > > > so it's ok to replace them with build id data: > > > > union { > > > > struct { > > > > u32 maj; > > > > u32 min; > > > > u64 ino; > > > > u64 ino_generation; > > > > }; > > > > struct { > > > > u8 build_id[20]; > > > > u8 build_id_size; > > > What's the purpose of a size field for a fixed size array? Also, I'd > > > flip the order of these fields, first have the size and then the array. > > There can be different types of build-ids, with different sizes, > > flipping the order of the fields is indeed sensible, as we could then > > support even larger build_ids if the need arises :) > 3 whole bytes.. whooo! Hey, I agreed with you, flip the order of the fields, right? :-) - Arnaldo