[tip:perf/core] perf top: Add option to set the number of thread for event synthesize

From: tip-bot for Kan Liang
Date: Tue Oct 03 2017 - 12:49:33 EST

Commit-ID: 0c6b499495e928777c41ca2de4fbb58788269690
Gitweb: https://git.kernel.org/tip/0c6b499495e928777c41ca2de4fbb58788269690
Author: Kan Liang <kan.liang@xxxxxxxxx>
AuthorDate: Fri, 29 Sep 2017 07:47:55 -0700
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 3 Oct 2017 09:27:54 -0300

perf top: Add option to set the number of thread for event synthesize

Using UINT_MAX to indicate the default thread#, which is the max number
of online CPU.

Committer testing:

# perf trace --no-inherit -e clone -o /tmp/output perf top --num-thread-synthesize 9
# cat /tmp/output
? ( ? ): ... [continued]: clone()) = 26651 (perf)
0.059 ( 0.010 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5bfac44f30, parent_tidptr: 0x7f5bfac459d0, child_tidptr: 0x7f5bfac459d0, tls: 0x7f5bfac45700) = 26652 (perf)
0.116 ( 0.014 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5bfa443f30, parent_tidptr: 0x7f5bfa4449d0, child_tidptr: 0x7f5bfa4449d0, tls: 0x7f5bfa444700) = 26653 (perf)
0.141 ( 0.009 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5bf9c42f30, parent_tidptr: 0x7f5bf9c439d0, child_tidptr: 0x7f5bf9c439d0, tls: 0x7f5bf9c43700) = 26654 (perf)
0.160 ( 0.012 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5bf9441f30, parent_tidptr: 0x7f5bf94429d0, child_tidptr: 0x7f5bf94429d0, tls: 0x7f5bf9442700) = 26655 (perf)
0.232 ( 0.013 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5bf8c40f30, parent_tidptr: 0x7f5bf8c419d0, child_tidptr: 0x7f5bf8c419d0, tls: 0x7f5bf8c41700) = 26656 (perf)
0.393 ( 0.011 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5be3ffef30, parent_tidptr: 0x7f5be3fff9d0, child_tidptr: 0x7f5be3fff9d0, tls: 0x7f5be3fff700) = 26657 (perf)
0.802 ( 0.012 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5be37fdf30, parent_tidptr: 0x7f5be37fe9d0, child_tidptr: 0x7f5be37fe9d0, tls: 0x7f5be37fe700) = 26658 (perf)
1.411 ( 0.022 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5be2ffcf30, parent_tidptr: 0x7f5be2ffd9d0, child_tidptr: 0x7f5be2ffd9d0, tls: 0x7f5be2ffd700) = 26659 (perf)
246.422 ( 0.042 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f5be2ffcf30, parent_tidptr: 0x7f5be2ffd9d0, child_tidptr: 0x7f5be2ffd9d0, tls: 0x7f5be2ffd700) = 26660 (perf)
#

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Lukasz Odzioba <lukasz.odzioba@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1506696477-146932-5-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-top.txt | 3 +++
tools/perf/builtin-top.c | 11 ++++++++---
tools/perf/util/event.c | 5 ++++-
tools/perf/util/top.h | 1 +
4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index d864ea6..4353262 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -240,6 +240,9 @@ Default is to monitor all CPUS.
--force::
Don't do ownership validation.

+--num-thread-synthesize::
+ The number of threads to run when synthesizing events for existing processes.
+ By default, the number of threads equals to the number of online CPUs.

INTERACTIVE PROMPTING KEYS
--------------------------
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index bc31b93..477a869 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -958,14 +958,16 @@ static int __cmd_top(struct perf_top *top)
if (perf_session__register_idle_thread(top->session) < 0)
goto out_delete;

- perf_set_multithreaded();
+ if (top->nr_threads_synthesize > 1)
+ perf_set_multithreaded();

machine__synthesize_threads(&top->session->machines.host, &opts->target,
top->evlist->threads, false,
opts->proc_map_timeout,
- (unsigned int)sysconf(_SC_NPROCESSORS_ONLN));
+ top->nr_threads_synthesize);

- perf_set_singlethreaded();
+ if (top->nr_threads_synthesize > 1)
+ perf_set_singlethreaded();

if (perf_hpp_list.socket) {
ret = perf_env__read_cpu_topology_map(&perf_env);
@@ -1118,6 +1120,7 @@ int cmd_top(int argc, const char **argv)
},
.max_stack = sysctl_perf_event_max_stack,
.sym_pcnt_filter = 5,
+ .nr_threads_synthesize = UINT_MAX,
};
struct record_opts *opts = &top.record_opts;
struct target *target = &opts->target;
@@ -1227,6 +1230,8 @@ int cmd_top(int argc, const char **argv)
OPT_BOOLEAN(0, "hierarchy", &symbol_conf.report_hierarchy,
"Show entries in a hierarchy"),
OPT_BOOLEAN(0, "force", &symbol_conf.force, "don't complain, do it"),
+ OPT_UINTEGER(0, "num-thread-synthesize", &top.nr_threads_synthesize,
+ "number of thread to run event synthesize"),
OPT_END()
};
const char * const top_usage[] = {
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 0e678dd..47eff47 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -790,7 +790,10 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
if (n < 0)
return err;

- thread_nr = nr_threads_synthesize;
+ if (nr_threads_synthesize == UINT_MAX)
+ thread_nr = sysconf(_SC_NPROCESSORS_ONLN);
+ else
+ thread_nr = nr_threads_synthesize;

if (thread_nr <= 1) {
err = __perf_event__synthesize_threads(tool, process,
diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index 9bdfb78..f4296e1 100644
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -37,6 +37,7 @@ struct perf_top {
int sym_pcnt_filter;
const char *sym_filter;
float min_percent;
+ unsigned int nr_threads_synthesize;
};

#define CONSOLE_CLEAR ""