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@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Lukasz Odzioba <lukasz.odzioba@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1506696477-146932-5-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index d864ea6fd367efb63e1a9411f6e74e8d42ab3428..4353262bc462b05cc3c4008c1a39e06ee76b758b 100644 (file)
--- 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 bc31b93cc1d8ffbf1e8d80cc31c2cda981a013f8..477a8699f0b501e3c71a711fd6a5a336645a1c46 100644 (file)
--- 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 0e678dd6bdbec36bcc2c6aba059c75c346e8b542..47eff4767edb4797b9426e90065d0fc23dc4c616 100644 (file)
--- 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 9bdfb78a9a35d2b27a3c38bf5234af0af1f7985d..f4296e1e3bb8c0e9c0e4ade3d38214ba8f6fc5d8 100644 (file)
--- 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 "\e[H\e[2J"