Re: [PATCH v8 08/18] perf ftrace: add support for tracing option 'func_stack_trace'
On Fri, Aug 14, 2020 at 09:24:40AM -0300, Arnaldo Carvalho de Melo wrote: > Em Sat, Aug 08, 2020 at 10:31:31AM +0800, Changbin Du escreveu: > > This adds support to display call trace for function tracer. To do this, > > just specify a '--func-opts call-graph' option. > > Applied, thanks for providing the usage example and the output of the > tool, please consider making this more compact and similar to the other > perf tools as: > ># perf ftrace -g -T vfs_read > > # perf report -h -g > >Usage: perf report [] > > -g, --call-graph > > Display call graph (stack chain/backtrace): > > print_type: call graph printing style > (graph|flat|fractal|folded|none) > threshold: minimum call graph > inclusion threshold () > print_limit:maximum number of call > graph entry () > order: call graph order > (caller|callee) > sort_key: call graph sort key > (function|address) > branch: include last branch info to > call graph (branch) > value: call graph value > (percent|period|count) > > Default: graph,0.5,caller,function,percent > > # > > Is there a way to ask for a limit in the number of levels? That is > similar to /proc/sys/kernel/perf_event_max_stack (system wide) and > perf_event_attr.sample_max_stack (per event)? > No, there is no such limit for function tracer yet (kernel doesn't support it). It just backtraces from current to top. For graph tracer, the option is --graph-opts depth=. > One can ask for that per event: > > # perf trace -e sched:*_wakeup/max-stack=2/ -e sched:*switch/max-stack=5/ > --max-events=4 > 0.000 migration/0/12 sched:sched_switch(prev_comm: "migration/0", > prev_pid: 12 (migration/0), prev_prio: 0, prev_state: 1, next_comm: > "swapper/0", next_pid: 0, next_prio: 120) >__schedule ([kernel.kallsyms]) >__schedule ([kernel.kallsyms]) >schedule ([kernel.kallsyms]) >smpboot_thread_fn ([kernel.kallsyms]) >kthread ([kernel.kallsyms]) > 2.381 :0/0 sched:sched_wakeup(comm: "PacerThread", pid: 111637 > (PacerThread), prio: 120, success: 1, target_cpu: 0) >ttwu_do_wakeup ([kernel.kallsyms]) >ttwu_do_wakeup ([kernel.kallsyms]) > 2.387 :0/0 sched:sched_switch(prev_comm: "swapper/0", prev_pid: 0, > prev_prio: 120, prev_state: 0, next_comm: "PacerThread", next_pid: 111637 > (PacerThread), next_prio: 120) >__schedule ([kernel.kallsyms]) >__schedule ([kernel.kallsyms]) >schedule_idle ([kernel.kallsyms]) >do_idle ([kernel.kallsyms]) >cpu_startup_entry ([kernel.kallsyms]) > 2.410 PacerThread/111637 sched:sched_switch(prev_comm: "PacerThread", > prev_pid: 111637 (PacerThread), prev_prio: 120, prev_state: 1, next_comm: > "swapper/0", next_pid: 0, next_prio: 120) >__schedule ([kernel.kallsyms]) >__schedule ([kernel.kallsyms]) >schedule ([kernel.kallsyms]) >futex_wait_queue_me ([kernel.kallsyms]) >futex_wait ([kernel.kallsyms]) > # > > - Arnaldo > > > $ sudo perf ftrace -T vfs_read --func-opts call-graph > > iio-sensor-prox-855 [003] 6168.369657: vfs_read <-ksys_read > > iio-sensor-prox-855 [003] 6168.369677: > > => vfs_read > > => ksys_read > > => __x64_sys_read > > => do_syscall_64 > > => entry_SYSCALL_64_after_hwframe > > ... > > > > Signed-off-by: Changbin Du > > > > --- > > v3: switch to uniform option --func-opts. > > v2: option name '-s' -> '--func-call-graph' > > --- > > tools/perf/Documentation/perf-ftrace.txt | 4 +++ > > tools/perf/builtin-ftrace.c | 42 > > 2 files changed, 46 insertions(+) > > > > diff --git a/tools/perf/Documentation/perf-ftrace.txt > > b/tools/perf/Documentation/perf-ftrace.txt > > index c46d0a09b38c..8f08ad0992c2 100644 > > --- a/tools/perf/Documentation/perf-ftrace.txt > > +++ b/tools/perf/Documentation/perf-ftrace.txt > > @@ -76,6 +76,10 @@ OPTIONS > > specify multiple functions (or glob patterns). It will be > > passed to 'set_ftrace_notrace' in tracefs. > > > > +--func-opts:: > > + List of options allowed to set: > > +
Re: [PATCH v8 08/18] perf ftrace: add support for tracing option 'func_stack_trace'
Em Sat, Aug 08, 2020 at 10:31:31AM +0800, Changbin Du escreveu: > This adds support to display call trace for function tracer. To do this, > just specify a '--func-opts call-graph' option. Applied, thanks for providing the usage example and the output of the tool, please consider making this more compact and similar to the other perf tools as: # perf ftrace -g -T vfs_read # perf report -h -g Usage: perf report [] -g, --call-graph Display call graph (stack chain/backtrace): print_type: call graph printing style (graph|flat|fractal|folded|none) threshold: minimum call graph inclusion threshold () print_limit:maximum number of call graph entry () order: call graph order (caller|callee) sort_key: call graph sort key (function|address) branch: include last branch info to call graph (branch) value: call graph value (percent|period|count) Default: graph,0.5,caller,function,percent # Is there a way to ask for a limit in the number of levels? That is similar to /proc/sys/kernel/perf_event_max_stack (system wide) and perf_event_attr.sample_max_stack (per event)? One can ask for that per event: # perf trace -e sched:*_wakeup/max-stack=2/ -e sched:*switch/max-stack=5/ --max-events=4 0.000 migration/0/12 sched:sched_switch(prev_comm: "migration/0", prev_pid: 12 (migration/0), prev_prio: 0, prev_state: 1, next_comm: "swapper/0", next_pid: 0, next_prio: 120) __schedule ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) smpboot_thread_fn ([kernel.kallsyms]) kthread ([kernel.kallsyms]) 2.381 :0/0 sched:sched_wakeup(comm: "PacerThread", pid: 111637 (PacerThread), prio: 120, success: 1, target_cpu: 0) ttwu_do_wakeup ([kernel.kallsyms]) ttwu_do_wakeup ([kernel.kallsyms]) 2.387 :0/0 sched:sched_switch(prev_comm: "swapper/0", prev_pid: 0, prev_prio: 120, prev_state: 0, next_comm: "PacerThread", next_pid: 111637 (PacerThread), next_prio: 120) __schedule ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule_idle ([kernel.kallsyms]) do_idle ([kernel.kallsyms]) cpu_startup_entry ([kernel.kallsyms]) 2.410 PacerThread/111637 sched:sched_switch(prev_comm: "PacerThread", prev_pid: 111637 (PacerThread), prev_prio: 120, prev_state: 1, next_comm: "swapper/0", next_pid: 0, next_prio: 120) __schedule ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) futex_wait_queue_me ([kernel.kallsyms]) futex_wait ([kernel.kallsyms]) # - Arnaldo > $ sudo perf ftrace -T vfs_read --func-opts call-graph > iio-sensor-prox-855 [003] 6168.369657: vfs_read <-ksys_read > iio-sensor-prox-855 [003] 6168.369677: > => vfs_read > => ksys_read > => __x64_sys_read > => do_syscall_64 > => entry_SYSCALL_64_after_hwframe > ... > > Signed-off-by: Changbin Du > > --- > v3: switch to uniform option --func-opts. > v2: option name '-s' -> '--func-call-graph' > --- > tools/perf/Documentation/perf-ftrace.txt | 4 +++ > tools/perf/builtin-ftrace.c | 42 > 2 files changed, 46 insertions(+) > > diff --git a/tools/perf/Documentation/perf-ftrace.txt > b/tools/perf/Documentation/perf-ftrace.txt > index c46d0a09b38c..8f08ad0992c2 100644 > --- a/tools/perf/Documentation/perf-ftrace.txt > +++ b/tools/perf/Documentation/perf-ftrace.txt > @@ -76,6 +76,10 @@ OPTIONS > specify multiple functions (or glob patterns). It will be > passed to 'set_ftrace_notrace' in tracefs. > > +--func-opts:: > + List of options allowed to set: > + call-graph - Display kernel stack trace for function tracer. > + > -G:: > --graph-funcs=:: > Select function_graph tracer and set graph filter on the given > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c > index 07b81d0c1658..469b89748c42 100644 > --- a/tools/perf/builtin-ftrace.c > +++ b/tools/perf/builtin-ftrace.c > @@ -27,6 +27,7 @@ > #include "util/cap.h" > #include "util/config.h" > #include "util/units.h" >
[PATCH v8 08/18] perf ftrace: add support for tracing option 'func_stack_trace'
This adds support to display call trace for function tracer. To do this,
just specify a '--func-opts call-graph' option.
$ sudo perf ftrace -T vfs_read --func-opts call-graph
iio-sensor-prox-855 [003] 6168.369657: vfs_read <-ksys_read
iio-sensor-prox-855 [003] 6168.369677:
=> vfs_read
=> ksys_read
=> __x64_sys_read
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
...
Signed-off-by: Changbin Du
---
v3: switch to uniform option --func-opts.
v2: option name '-s' -> '--func-call-graph'
---
tools/perf/Documentation/perf-ftrace.txt | 4 +++
tools/perf/builtin-ftrace.c | 42
2 files changed, 46 insertions(+)
diff --git a/tools/perf/Documentation/perf-ftrace.txt
b/tools/perf/Documentation/perf-ftrace.txt
index c46d0a09b38c..8f08ad0992c2 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -76,6 +76,10 @@ OPTIONS
specify multiple functions (or glob patterns). It will be
passed to 'set_ftrace_notrace' in tracefs.
+--func-opts::
+ List of options allowed to set:
+ call-graph - Display kernel stack trace for function tracer.
+
-G::
--graph-funcs=::
Select function_graph tracer and set graph filter on the given
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 07b81d0c1658..469b89748c42 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -27,6 +27,7 @@
#include "util/cap.h"
#include "util/config.h"
#include "util/units.h"
+#include "util/parse-sublevel-options.h"
#define DEFAULT_TRACER "function_graph"
@@ -42,6 +43,7 @@ struct perf_ftrace {
int graph_depth;
unsigned long percpu_buffer_size;
boolinherit;
+ int func_stack_trace;
};
struct filter_entry {
@@ -202,6 +204,7 @@ static void reset_tracing_filters(void);
static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
{
write_tracing_option_file("function-fork", "0");
+ write_tracing_option_file("func_stack_trace", "0");
}
static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -278,6 +281,17 @@ static int set_tracing_cpu(struct perf_ftrace *ftrace)
return set_tracing_cpumask(cpumap);
}
+static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
+{
+ if (!ftrace->func_stack_trace)
+ return 0;
+
+ if (write_tracing_option_file("func_stack_trace", "1") < 0)
+ return -1;
+
+ return 0;
+}
+
static int reset_tracing_cpu(void)
{
struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
@@ -426,6 +440,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int
argc, const char **argv)
goto out_reset;
}
+ if (set_tracing_func_stack_trace(ftrace) < 0) {
+ pr_err("failed to set tracing option func_stack_trace\n");
+ goto out_reset;
+ }
+
if (set_tracing_filters(ftrace) < 0) {
pr_err("failed to set tracing filters\n");
goto out_reset;
@@ -598,6 +617,26 @@ static int parse_buffer_size(const struct option *opt,
return -1;
}
+static int parse_func_tracer_opts(const struct option *opt,
+ const char *str, int unset)
+{
+ int ret;
+ struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
+ struct sublevel_option func_tracer_opts[] = {
+ { .name = "call-graph", .value_ptr = >func_stack_trace
},
+ { .name = NULL, }
+ };
+
+ if (unset)
+ return 0;
+
+ ret = perf_parse_sublevel_options(str, func_tracer_opts);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static void select_tracer(struct perf_ftrace *ftrace)
{
bool graph = !list_empty(>graph_funcs) ||
@@ -645,6 +684,9 @@ int cmd_ftrace(int argc, const char **argv)
parse_filter_func),
OPT_CALLBACK('N', "notrace-funcs", , "func",
"do not trace given functions", parse_filter_func),
+ OPT_CALLBACK(0, "func-opts", , "options",
+"function tracer options, available options: call-graph",
+parse_func_tracer_opts),
OPT_CALLBACK('G', "graph-funcs", _funcs, "func",
"trace given functions using function_graph tracer",
parse_filter_func),
--
2.25.1
