Re: [PATCH v1 0/3] Remove BPF arrays from perf event parsing

From: Arnaldo Carvalho de Melo
Date: Fri Jul 28 2023 - 10:29:43 EST


Em Thu, Jul 27, 2023 at 05:12:09PM -0700, Ian Rogers escreveu:
> Event parsing was recently refactored:
> https://lore.kernel.org/all/20230502223851.2234828-1-irogers@xxxxxxxxxx/
>
> During these changes I wanted to get coverage of all parts of the
> parse-events.y and found that I couldn't test the array code.
>
> The first patch fixes a BPF testing issue.
> The 2nd and 3rd patch remove the BPF array event parsing code so that
> it isn't adding complexity to event parsing.

Thanks, applied and tested that 'perf trace' using the old BPF perf
integration continues to work modulo the sockaddr collectors, but that
is a problem with a newer kernel BPF verifier or clang, will
investigate.

With those commented out:

diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
index 9a03189d33d3816a..97871e2bd3a47bdf 100644
--- a/tools/perf/examples/bpf/augmented_raw_syscalls.c
+++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
@@ -176,6 +176,7 @@ int syscall_unaugmented(struct syscall_enter_args *args)
return 1;
}

+#if 0
/*
* These will be tail_called from SEC("raw_syscalls:sys_enter"), so will find in
* augmented_args_tmp what was read by that raw_syscalls:sys_enter and go
@@ -219,6 +220,7 @@ int sys_enter_sendto(struct syscall_enter_args *args)

return augmented__output(args, augmented_args, len + socklen);
}
+#endif

SEC("!syscalls:sys_enter_open")
int sys_enter_open(struct syscall_enter_args *args)




# perf trace -e /home/acme/git/perf-tools-next/tools/perf/examples/bpf/augmented_raw_syscalls.c,open*
0.000 systemd-oomd/952 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
95.302 thermald/1231 openat(dfd: CWD, filename: "/sys/class/powercap/intel-rapl/intel-rapl:0/intel-rapl:0:2/energy_uj") = 13
95.586 thermald/1231 openat(dfd: CWD, filename: "/sys/class/powercap/intel-rapl/intel-rapl:0/energy_uj") = 13
95.857 thermald/1231 openat(dfd: CWD, filename: "/sys/class/thermal/thermal_zone2/temp") = 13
250.064 systemd-oomd/952 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
500.054 systemd-oomd/952 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
500.472 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
500.669 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
500.777 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/memory.min", flags: RDONLY|CLOEXEC) = 12
500.873 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/memory.low", flags: RDONLY|CLOEXEC) = 12
500.968 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/memory.swap.current", flags: RDONLY|CLOEXEC) = 12
501.062 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/memory.stat", flags: RDONLY|CLOEXEC) = 12
501.435 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
501.585 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
501.676 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.min", flags: RDONLY|CLOEXEC) = 12
501.761 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.low", flags: RDONLY|CLOEXEC) = 12
501.845 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.swap.current", flags: RDONLY|CLOEXEC) = 12
501.929 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.stat", flags: RDONLY|CLOEXEC) = 12
502.118 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-gnome\x2dsession\x2dmanager.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
502.272 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-gnome\x2dsession\x2dmanager.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
502.367 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-gnome\x2dsession\x2dmanager.slice/memory.min", flags: RDONLY|CLOEXEC) = 12
502.454 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-gnome\x2dsession\x2dmanager.slice/memory.low", flags: RDONLY|CLOEXEC) = 12
502.542 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-gnome\x2dsession\x2dmanager.slice/memory.swap.current", flags: RDONLY|CLOEXEC) = 12
502.628 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-gnome\x2dsession\x2dmanager.slice/memory.stat", flags: RDONLY|CLOEXEC) = 12
502.796 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
502.928 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
503.037 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/memory.min", flags: RDONLY|CLOEXEC) = 12
503.162 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/memory.low", flags: RDONLY|CLOEXEC) = 12
503.255 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/memory.swap.current", flags: RDONLY|CLOEXEC) = 12
503.341 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/memory.stat", flags: RDONLY|CLOEXEC) = 12
503.495 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/system.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
503.620 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/system.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
503.703 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/system.slice/memory.min", flags: RDONLY|CLOEXEC) = 12
503.782 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/system.slice/memory.low", flags: RDONLY|CLOEXEC) = 12
503.861 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/system.slice/memory.swap.current", flags: RDONLY|CLOEXEC) = 12
503.939 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/system.slice/memory.stat", flags: RDONLY|CLOEXEC) = 12
504.079 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1001.slice/user@1001.service/app.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
504.240 systemd-oomd/952 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1001.slice/user@1001.service/app.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
^C

- Arnaldo

> Ian Rogers (3):
> perf parse-event: Avoid BPF test segv
> perf tools: Revert enable indices setting syntax for BPF map
> perf parse-events: Remove array remnants
>
> tools/perf/util/bpf-loader.c | 101 ---------------------------
> tools/perf/util/parse-events.c | 18 +----
> tools/perf/util/parse-events.h | 10 ---
> tools/perf/util/parse-events.l | 11 ---
> tools/perf/util/parse-events.y | 122 ---------------------------------
> 5 files changed, 2 insertions(+), 260 deletions(-)
>
> --
> 2.41.0.487.g6d72f3e995-goog
>

--

- Arnaldo