From c3e78a3403dabcb7115c2fb7b538a1095d168cd5 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 9 Jul 2019 16:36:45 -0300 Subject: [PATCH] perf trace: Auto bump rlimit(MEMLOCK) for eBPF maps sake Circa v5.2 this started to fail: # perf trace -e /wb/augmented_raw_syscalls.o event syntax error: '/wb/augmented_raw_syscalls.o' \___ Operation not permitted (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf trace [] [] or: perf trace [] -- [] or: perf trace record [] [] or: perf trace record [] -- [] -e, --event event/syscall selector. use 'perf list' to list available events # In verbose mode we some -EPERM when creating a BPF map: # perf trace -v -e /wb/augmented_raw_syscalls.o libbpf: failed to create map (name: '__augmented_syscalls__'): Operation not permitted libbpf: failed to load object '/wb/augmented_raw_syscalls.o' bpf: load objects failed: err=-1: (Operation not permitted) event syntax error: '/wb/augmented_raw_syscalls.o' \___ Operation not permitted (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf trace [] [] or: perf trace [] -- [] or: perf trace record [] [] or: perf trace record [] -- [] -e, --event event/syscall selector. use 'perf list' to list available events # If we bumped 'ulimit -l 128' to get it from the 64k default to double that, it worked, so use the recently added rlimit__bump_memlock() helper: # perf trace -e /wb/augmented_raw_syscalls.o -e open*,*sleep sleep 1 0.000 ( 0.007 ms): sleep/28042 openat(dfd: CWD, filename: "/etc/ld.so.cache", flags: RDONLY|CLOEXEC) = 3 0.022 ( 0.004 ms): sleep/28042 openat(dfd: CWD, filename: "/lib64/libc.so.6", flags: RDONLY|CLOEXEC) = 3 0.201 ( 0.007 ms): sleep/28042 openat(dfd: CWD, filename: "", flags: RDONLY|CLOEXEC) = 3 0.241 (1000.421 ms): sleep/28042 nanosleep(rqtp: 0x7ffd6c3e6ed0) = 0 # Cc: Adrian Hunter Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-j6f2ioa6hj9dinzpjvlhcjoc@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 1aa2ed096f65..4f0bbffee05f 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -19,6 +19,7 @@ #include #include #include "util/bpf_map.h" +#include "util/rlimit.h" #include "builtin.h" #include "util/cgroup.h" #include "util/color.h" @@ -3864,6 +3865,15 @@ int cmd_trace(int argc, const char **argv) goto out; } + /* + * Parsing .perfconfig may entail creating a BPF event, that may need + * to create BPF maps, so bump RLIM_MEMLOCK as the default 64K setting + * is too small. This affects just this process, not touching the + * global setting. If it fails we'll get something in 'perf trace -v' + * to help diagnose the problem. + */ + rlimit__bump_memlock(); + err = perf_config(trace__config, &trace); if (err) goto out;