Re: [PATCH 03/24] perf: Add build id data in mmap2 event

From: Jiri Olsa
Date: Thu Nov 26 2020 - 11:55:34 EST


On Tue, Nov 17, 2020 at 12:13:34PM +0100, Peter Zijlstra wrote:
> On Tue, Nov 17, 2020 at 12:00:32PM +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, which 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_size;
> > u8 __reserved_1;
> > u16 __reserved_2;
> > u8 build_id[20];
> > };
> > };
> >
> > Replaced maj/min/ino/ino_generation fields give us size
> > of 24 bytes. We use 20 bytes for build id data, 1 byte
> > for size and rest is unused.
> >
> > There's new misc bit for mmap2 to signal there's build
> > id data in it:
> >
> > #define PERF_RECORD_MISC_MMAP_BUILD_ID (1 << 14)
> >
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
>
> Seems sane enough; how do we want to route this?
>
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
>

I still need review from bpf folks, but then I guess
Arnaldo's tree would be the best, because it's mostly
tools changes.. I'm sending new version

jirka