On Thu, Apr 24, 2025 at 11:20:11AM -0700, Andrii Nakryiko wrote: > On Thu, Apr 24, 2025 at 9:29 AM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > > On Thu, Apr 24, 2025 at 5:49 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote: > > > > > > On Wed, Apr 23, 2025 at 10:33:18AM -0700, Andrii Nakryiko wrote: > > > > On Mon, Apr 21, 2025 at 2:46 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > > > > > > > > > > Using 5-byte nop for x86 usdt probes so we can switch > > > > > to optimized uprobe them. > > > > > > > > > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> > > > > > --- > > > > > tools/testing/selftests/bpf/sdt.h | 9 ++++++++- > > > > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > > > > > > > > > > So sdt.h is an exact copy/paste from systemtap-sdt sources. I'd prefer > > > > to not modify it unnecessarily. > > > > > > > > How about we copy/paste usdt.h ([0]) and use *that* for your > > > > benchmarks? I've already anticipated the need to change nop > > > > instruction, so you won't even need to modify the usdt.h file itself, > > > > just > > > > > > > > #define USDT_NOP .byte 0x0f, 0x1f, 0x44, 0x00, 0x00 > > > > > > > > before #include "usdt.h" > > > > > > > > > sounds good, but it seems we need bit more changes for that, > > > so far I ended up with: > > > > > > - __usdt_asm1(990: USDT_NOP) \ > > > + __usdt_asm5(990: USDT_NOP) \ > > > > > > but it still won't compile, will need to spend more time on that, > > > unless you have better solution > > > > > > > Use > > > > #define USDT_NOP .ascii "\x0F\x1F\x44\x00\x00" > > > > for now, I'll need to improve macro magic to handle instructions with > > commas in them... > > Ok, fixed in [0]. If you get the latest version, the .byte approach > will work (I have tests in CI now to validate this). > > [0] https://github.com/libbpf/usdt/pull/12 yep, works nicely, thanks jirka
