perf trace: Add --max-stack knob (c6d4a494) · Commits · 戴 / test

tools/perf/Documentation/perf-trace.txt

+9 −0

Original line number	Diff line number	Diff line
		@@ -129,6 +129,15 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
		--event::
		Trace other events, see 'perf list' for a complete list.

		--max-stack::
		Set the stack depth limit when parsing the callchain, anything
		beyond the specified depth will be ignored. Note that at this point
		this is just about the presentation part, i.e. the kernel is still
		not limiting, the overhead of callchains needs to be set via the
		knobs in --call-graph dwarf.

		Default: 127

		--proc-map-timeout::
		When processing pre-existing threads /proc/XXX/mmap, it may take a long time,
		because the file may be huge. A time out is needed in such cases.

tools/perf/builtin-trace.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -46,6 +46,7 @@
		#include <linux/audit.h>
		#include <sys/ptrace.h>
		#include <linux/random.h>
		#include <linux/stringify.h>

		#ifndef O_CLOEXEC
		# define O_CLOEXEC 02000000
		@@ -106,6 +107,7 @@ struct trace {
		u64 vfs_getname,
		proc_getname;
		} stats;
		unsigned int max_stack;
		bool not_ev_qualifier;
		bool live;
		bool full_time;
		@@ -1892,7 +1894,7 @@ static int trace__fprintf_callchain(struct trace trace, struct perf_evsel evse

		if (machine__resolve(trace->host, &al, sample) < 0 \|\|
		thread__resolve_callchain(al.thread, &callchain_cursor, evsel,
		sample, NULL, NULL, scripting_max_stack)) {
		sample, NULL, NULL, trace->max_stack)) {
		pr_err("Problem processing %s callchain, skipping...\n",
		perf_evsel__name(evsel));
		return 0;
		@@ -3029,6 +3031,7 @@ int cmd_trace(int argc, const char *argv, const char prefix __maybe_unused)
		.show_comm = true,
		.trace_syscalls = true,
		.kernel_syscallchains = false,
		.max_stack = PERF_MAX_STACK_DEPTH,
		};
		const char *output_name = NULL;
		const char *ev_qualifier_str = NULL;
		@@ -3079,6 +3082,10 @@ int cmd_trace(int argc, const char *argv, const char prefix __maybe_unused)
		&record_parse_callchain_opt),
		OPT_BOOLEAN(0, "kernel-syscall-graph", &trace.kernel_syscallchains,
		"Show the kernel callchains on the syscall exit path"),
		OPT_UINTEGER(0, "max-stack", &trace.max_stack,
		"Set the maximum stack depth when parsing the callchain, "
		"anything beyond the specified depth will be ignored. "
		"Default: " __stringify(PERF_MAX_STACK_DEPTH)),
		OPT_UINTEGER(0, "proc-map-timeout", &trace.opts.proc_map_timeout,
		"per thread proc mmap processing timeout in ms"),
		OPT_END()

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