mirror of
https://github.com/torvalds/linux.git
synced 2026-03-14 00:56:20 +01:00
45641096c9
When CONFIG_HIST_TRIGGERS_DEBUG is enabled, each trace event has a
"hist_debug" file that explains the histogram internal data. This is very
useful for debugging histograms.
One bit of data that was missing from this file was what function a
histogram field uses to process its data. The hist_field structure now has
a fn_num that is used by a switch statement in hist_fn_call() to call a
function directly (to avoid spectre mitigations).
Instead of displaying that number, create a string array that maps to the
histogram function enums so that the function for a field may be
displayed:
~# cat /sys/kernel/tracing/events/sched/sched_switch/hist_debug
[..]
hist_data: 0000000043d62762
n_vals: 2
n_keys: 1
n_fields: 3
val fields:
hist_data->fields[0]:
flags:
VAL: HIST_FIELD_FL_HITCOUNT
type: u64
size: 8
is_signed: 0
function: hist_field_counter()
hist_data->fields[1]:
flags:
HIST_FIELD_FL_VAR
var.name: __arg_3921_2
var.idx (into tracing_map_elt.vars[]): 0
type: unsigned long[]
size: 128
is_signed: 0
function: hist_field_nop()
key fields:
hist_data->fields[2]:
flags:
HIST_FIELD_FL_KEY
ftrace_event_field name: prev_pid
type: pid_t
size: 8
is_signed: 1
function: hist_field_s32()
The "function:" field above is added.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260122203822.58df4d80@gandalf.local.home
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
||
|---|---|---|
| .. | ||
| rv | ||
| blktrace.c | ||
| bpf_trace.c | ||
| bpf_trace.h | ||
| error_report-traces.c | ||
| fgraph.c | ||
| fprobe.c | ||
| ftrace.c | ||
| ftrace_internal.h | ||
| Kconfig | ||
| kprobe_event_gen_test.c | ||
| Makefile | ||
| pid_list.c | ||
| pid_list.h | ||
| power-traces.c | ||
| preemptirq_delay_test.c | ||
| rethook.c | ||
| ring_buffer.c | ||
| ring_buffer_benchmark.c | ||
| rpm-traces.c | ||
| synth_event_gen_test.c | ||
| trace.c | ||
| trace.h | ||
| trace_benchmark.c | ||
| trace_benchmark.h | ||
| trace_boot.c | ||
| trace_branch.c | ||
| trace_btf.c | ||
| trace_btf.h | ||
| trace_clock.c | ||
| trace_dynevent.c | ||
| trace_dynevent.h | ||
| trace_entries.h | ||
| trace_eprobe.c | ||
| trace_event_perf.c | ||
| trace_events.c | ||
| trace_events_filter.c | ||
| trace_events_filter_test.h | ||
| trace_events_hist.c | ||
| trace_events_inject.c | ||
| trace_events_synth.c | ||
| trace_events_trigger.c | ||
| trace_events_user.c | ||
| trace_export.c | ||
| trace_fprobe.c | ||
| trace_functions.c | ||
| trace_functions_graph.c | ||
| trace_hwlat.c | ||
| trace_irqsoff.c | ||
| trace_kdb.c | ||
| trace_kprobe.c | ||
| trace_kprobe_selftest.c | ||
| trace_kprobe_selftest.h | ||
| trace_mmiotrace.c | ||
| trace_nop.c | ||
| trace_osnoise.c | ||
| trace_output.c | ||
| trace_output.h | ||
| trace_preemptirq.c | ||
| trace_printk.c | ||
| trace_probe.c | ||
| trace_probe.h | ||
| trace_probe_kernel.h | ||
| trace_probe_tmpl.h | ||
| trace_recursion_record.c | ||
| trace_sched_switch.c | ||
| trace_sched_wakeup.c | ||
| trace_selftest.c | ||
| trace_selftest_dynamic.c | ||
| trace_seq.c | ||
| trace_stack.c | ||
| trace_stat.c | ||
| trace_stat.h | ||
| trace_synth.h | ||
| trace_syscalls.c | ||
| trace_uprobe.c | ||
| tracing_map.c | ||
| tracing_map.h | ||