perf tools: Fix usage of max_stack sysctl

We cannot limit processing stacks from the current value of the sysctl,
as we may be processing perf.data files, possibly from other machines.

Instead use the old PERF_MAX_STACK_DEPTH, the sysctl default, that can
be overriden using --max-stack or equivalent.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Fixes: 4cb93446 ("perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack")
Link: http://lkml.kernel.org/n/tip-eqeutsr7n7wy0c36z24ytvii@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent bf8bddbf
......@@ -248,7 +248,7 @@ OPTIONS
Note that when using the --itrace option the synthesized callchain size
will override this value if the synthesized callchain size is bigger.
Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise.
Default: 127
-G::
--inverted::
......
......@@ -267,7 +267,7 @@ include::itrace.txt[]
Note that when using the --itrace option the synthesized callchain size
will override this value if the synthesized callchain size is bigger.
Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise.
Default: 127
--ns::
Use 9 decimal places when displaying time (i.e. show the nanoseconds)
......
......@@ -143,7 +143,8 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
Implies '--call-graph dwarf' when --call-graph not present on the
command line, on systems where DWARF unwinding was built in.
Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise.
Default: /proc/sys/kernel/perf_event_max_stack when present for
live sessions (without --input/-i), 127 otherwise.
--min-stack::
Set the stack depth limit when parsing the callchain, anything
......
......@@ -691,7 +691,7 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
.ordered_events = true,
.ordering_requires_timestamps = true,
},
.max_stack = sysctl_perf_event_max_stack,
.max_stack = PERF_MAX_STACK_DEPTH,
.pretty_printing_style = "normal",
.socket_filter = -1,
};
......
......@@ -2067,8 +2067,6 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
NULL
};
scripting_max_stack = sysctl_perf_event_max_stack;
setup_scripting();
argc = parse_options_subcommand(argc, argv, options, script_subcommands, script_usage,
......
......@@ -2905,7 +2905,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
mmap_pages_user_set = false;
if (trace.max_stack == UINT_MAX) {
trace.max_stack = sysctl_perf_event_max_stack;
trace.max_stack = input_name ? PERF_MAX_STACK_DEPTH : sysctl_perf_event_max_stack;
max_stack_user_set = false;
}
......
......@@ -298,8 +298,7 @@ static struct call_path *call_path_from_sample(struct db_export *dbe,
*/
callchain_param.order = ORDER_CALLER;
err = thread__resolve_callchain(thread, &callchain_cursor, evsel,
sample, NULL, NULL,
sysctl_perf_event_max_stack);
sample, NULL, NULL, PERF_MAX_STACK_DEPTH);
if (err) {
callchain_param.order = saved_order;
return NULL;
......
......@@ -264,8 +264,7 @@ static SV *perl_process_callchain(struct perf_sample *sample,
goto exit;
if (thread__resolve_callchain(al->thread, &callchain_cursor, evsel,
sample, NULL, NULL,
sysctl_perf_event_max_stack) != 0) {
sample, NULL, NULL, scripting_max_stack) != 0) {
pr_err("Failed to resolve callchain. Skipping\n");
goto exit;
}
......
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