diff options
| author | Ian Rogers <irogers@google.com> | 2026-09-28 11:25:58 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-10-01 17:47:15 +0200 |
| commit | e827cc9413abc43d93044bb23066fa81bbcb04be (patch) | |
| tree | 7739b0f49306bba2ff271f0b61474d3f01cfcb14 | |
| parent | 9ab6ea11e8adde1189d688b6e04953e22c7ca55c (diff) | |
perf trace: Add an option to disable syscall augmentation
'perf trace' falls back to the raw_syscalls tracepoints, filtering in user
space, when the augmentation BPF programs can't be loaded.
Add --no-syscall-augment to use that path even when they can, so both
can be tested.
Suggest it when tasks are lost, as the tracepoints' per-task events
don't limit how many tasks are traced.
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/Documentation/perf-trace.txt | 6 | ||||
| -rw-r--r-- | tools/perf/builtin-trace.c | 10 |
2 files changed, 15 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index d20b43ea3d37..fabb37258751 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -172,6 +172,12 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs. Trace system calls. This options is enabled by default, disable with --no-syscalls. +--syscall-augment:: + Augment system call arguments using BPF, the default when BPF support + is available. Disable with --no-syscall-augment to use the + raw_syscalls tracepoints instead, such as when more tasks are alive + at once than augmentation can trace. + --call-graph [mode,type,min[,limit],order[,key][,branch]]:: Setup and enable call-graph (stack chain/backtrace) recording. See `--call-graph` section in perf-record and perf-report diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 1be355a3ae22..c34c9f129836 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -216,6 +216,7 @@ struct trace { bool print_sample; bool show_tool_stats; bool trace_syscalls; + bool syscall_augment; bool libtraceevent_print; bool kernel_syscallchains; s16 args_alignment; @@ -5002,7 +5003,8 @@ out_disable: lost_tasks = augmented_syscalls__lost_tasks(); if (lost_tasks) color_fprintf(trace->output, PERF_COLOR_RED, - "LOST the syscalls of %d tasks, too many to trace at once!\n", + "LOST the syscalls of %d tasks, too many to trace at once!\n" + "Use --no-syscall-augment to trace them without augmentation.\n", lost_tasks); if (!err) { @@ -5788,6 +5790,7 @@ int cmd_trace(int argc, const char **argv) .show_arg_names = true, .args_alignment = 70, .trace_syscalls = false, + .syscall_augment = true, .kernel_syscallchains = false, .max_stack = UINT_MAX, .max_events = ULONG_MAX, @@ -5843,6 +5846,8 @@ int cmd_trace(int argc, const char **argv) OPT_CALLBACK_DEFAULT('F', "pf", &trace.trace_pgfaults, "all|maj|min", "Trace pagefaults", parse_pagefaults, "maj"), OPT_BOOLEAN(0, "syscalls", &trace.trace_syscalls, "Trace syscalls"), + OPT_BOOLEAN(0, "syscall-augment", &trace.syscall_augment, + "Augment syscalls using BPF"), OPT_BOOLEAN('f', "force", &trace.force, "don't complain, do it"), OPT_CALLBACK(0, "call-graph", &trace.opts, "record_mode[,record_size]", record_callchain_help, @@ -5982,6 +5987,9 @@ int cmd_trace(int argc, const char **argv) goto skip_augmentation; } + if (!trace.syscall_augment) + goto skip_augmentation; + err = augmented_syscalls__prepare(); if (err < 0) goto skip_augmentation; |