On Mon, Oct 7, 2019 at 2:00 AM Jesper Dangaard Brouer <brouer@xxxxxxxxxx> wrote: > > > On Mon, 7 Oct 2019 04:57:26 +0000 Eric Sage <eric@xxxxxxxx> wrote: > > > raw_tracepoints are an eBPF alternative to standard tracepoints which > > attach to a tracepoint without the perf layer being executed, making > > them faster. > > > > Since xdp_monitor is supposed to have as little impact on the system as > > possible it is switched to using them by append raw_ to the SEC names. > > > > There was also a small issues with 'samples/bpf/bpf_load' - it was > > loading the raw_tracepoints with the tracing subsystem name still > > attached, which the bpf syscall rejects with a No such file or directory > > error. This is now fixed. > > > > Signed-off-by: Eric Sage <eric@xxxxxxxx> > > --- > > samples/bpf/bpf_load.c | 5 +++-- > > samples/bpf/xdp_monitor_kern.c | 26 +++++++++++++------------- > > 2 files changed, 16 insertions(+), 15 deletions(-) > > If there is an issue in the loader 'samples/bpf/bpf_load.c' then we > should of-cause fix it, but you should be aware that we are in general > trying to deprecate this loader, and we want to convert users over to > libbpf. > > This patch seems like a good first step forward. Longer term, I would > like to see this converted into using libbpf. The library are missing > attach helpers for regular tracepoints, but for raw_tracepoints it does > contain bpf_raw_tracepoint_open(). libbpf has both bpf_program__attach_tracepoint() and bpf_program__attach_raw_tracepoint(), please use them, not lower-level bpf_raw_tracepoint_open(). See selftests/bpf/prog_tests/attach_probe.c for examples. > > You can see an example of how xdp_monitor have been converted into > using libbpf and raw_tracepoints here (by Jiri Olsa): > > https://github.com/xdp-project/xdp-tutorial/blob/master/tracing02-xdp-monitor/trace_prog_kern.c > > [...]
