perf evlist: Improve default event for s390

Frame pointer callchains are not supported on s390 and dwarf
callchains are only supported on software events.

Switch the default event from the hardware 'cycles' event to the
software 'cpu-clock' or 'task-clock' on s390 if callchains are
enabled. Move some of the target initialization earlier in builtin-top
and builtin-record, so it is ready for use by evlist__new_default.

If frame pointer callchains are requested on s390 show a
warning. Modify the '-g' option of `perf top` and `perf record` to
default to dwarf callchains on s390.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 59b8125d1b13a79ed22b9ddde79ff65ab1de0182..3276ffdc3141aa28d37b351022e63b22014a2b2d 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -55,6 +55,7 @@
 #include "asm/bug.h"
 #include "perf.h"
 #include "cputopo.h"
+#include "dwarf-regs.h"
 
 #include <errno.h>
 #include <inttypes.h>
@@ -2995,7 +2996,9 @@ static int record_callchain_opt(const struct option *opt,
                return 0;
        }
 
-       return record_opts__parse_callchain(opt->value, &callchain_param, "fp", unset);
+       return record_opts__parse_callchain(opt->value, &callchain_param,
+                                           EM_HOST != EM_S390 ? "fp" : "dwarf",
+                                           unset);
 }
 
 
@@ -4095,8 +4098,11 @@ int cmd_record(int argc, const char **argv)
 
        perf_debuginfod_setup(&record.debuginfod);
 
-       /* Make system wide (-a) the default target. */
-       if (!argc && target__none(&rec->opts.target))
+       /*
+        * Use system wide (-a) for the default target (ie. when no
+        * workload). User ID filtering also implies system-wide.
+        */
+       if ((!argc && target__none(&rec->opts.target)) || rec->uid_str)
                rec->opts.target.system_wide = true;
 
        if (nr_cgroups && !rec->opts.target.system_wide) {
@@ -4274,7 +4280,8 @@ int cmd_record(int argc, const char **argv)
                record.opts.tail_synthesize = true;
 
        if (rec->evlist->core.nr_entries == 0) {
-               struct evlist *def_evlist = evlist__new_default();
+               struct evlist *def_evlist = evlist__new_default(&rec->opts.target,
+                                                               callchain_param.enabled);
 
                if (!def_evlist)
                        goto out;
@@ -4303,9 +4310,6 @@ int cmd_record(int argc, const char **argv)
                err = parse_uid_filter(rec->evlist, uid);
                if (err)
                        goto out;
-
-               /* User ID filtering implies system wide. */
-               rec->opts.target.system_wide = true;
        }
 
        /* Enable ignoring missing threads when -p option is defined. */

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index b6726f4dffb3a2b75bf50699c007e015b020afb9..37950efb28aca8ccea0be1c2e3f65fc69eff1aff 100644 (file)
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -56,6 +56,7 @@
 #include "util/debug.h"
 #include "util/ordered-events.h"
 #include "util/pfm.h"
+#include "dwarf-regs.h"
 
 #include <assert.h>
 #include <elf.h>
@@ -1420,7 +1421,7 @@ callchain_opt(const struct option *opt, const char *arg __maybe_unused, int unse
                return 0;
        }
 
-       return parse_callchain_opt(opt, "fp", unset);
+       return parse_callchain_opt(opt, EM_HOST != EM_S390 ? "fp" : "dwarf", unset);
 }
 
 
@@ -1705,8 +1706,17 @@ int cmd_top(int argc, const char **argv)
        if (annotate_check_args() < 0)
                goto out_delete_evlist;
 
+       status = target__validate(target);
+       if (status) {
+               target__strerror(target, status, errbuf, BUFSIZ);
+               ui__warning("%s\n", errbuf);
+       }
+
+       if (target__none(target))
+               target->system_wide = true;
+
        if (!top.evlist->core.nr_entries) {
-               struct evlist *def_evlist = evlist__new_default();
+               struct evlist *def_evlist = evlist__new_default(target, callchain_param.enabled);
 
                if (!def_evlist)
                        goto out_delete_evlist;
@@ -1799,12 +1809,6 @@ int cmd_top(int argc, const char **argv)
                goto out_delete_evlist;
        }
 
-       status = target__validate(target);
-       if (status) {
-               target__strerror(target, status, errbuf, BUFSIZ);
-               ui__warning("%s\n", errbuf);
-       }
-
        if (top.uid_str) {
                uid_t uid = parse_uid(top.uid_str);
 
@@ -1818,9 +1822,6 @@ int cmd_top(int argc, const char **argv)
                        goto out_delete_evlist;
        }
 
-       if (target__none(target))
-               target->system_wide = true;
-
        if (evlist__create_maps(top.evlist, target) < 0) {
                ui__error("Couldn't create thread/CPU maps: %s\n",
                          errno == ENOENT ? "No such process" : str_error_r(errno, errbuf, sizeof(errbuf)));

diff --git a/tools/perf/tests/event_update.c b/tools/perf/tests/event_update.c
index cb9e6de2e03385b36bb319c99a7dbaf48f665546..facc65e29f20c2305e07f089462a4b0955f4f21e 100644 (file)
--- a/tools/perf/tests/event_update.c
+++ b/tools/perf/tests/event_update.c
@@ -8,6 +8,7 @@
 #include "header.h"
 #include "machine.h"
 #include "util/synthetic-events.h"
+#include "target.h"
 #include "tool.h"
 #include "tests.h"
 #include "debug.h"
@@ -81,7 +82,8 @@ static int test__event_update(struct test_suite *test __maybe_unused, int subtes
 {
        struct evsel *evsel;
        struct event_name tmp;
-       struct evlist *evlist = evlist__new_default();
+       struct target target = {};
+       struct evlist *evlist = evlist__new_default(&target, /*sample_callchains=*/false);
 
        TEST_ASSERT_VAL("failed to get evlist", evlist);
 

diff --git a/tools/perf/tests/expand-cgroup.c b/tools/perf/tests/expand-cgroup.c
index c7b32a220ca1cd6ccd101853d221d97c68c98d43..dd547f2f77cc832a81c827e859baad6780ef0e27 100644 (file)
--- a/tools/perf/tests/expand-cgroup.c
+++ b/tools/perf/tests/expand-cgroup.c
@@ -8,6 +8,7 @@
 #include "parse-events.h"
 #include "pmu-events/pmu-events.h"
 #include "pfm.h"
+#include "target.h"
 #include <subcmd/parse-options.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -99,7 +100,8 @@ out: for (i = 0; i < nr_events; i++)
 static int expand_default_events(void)
 {
        int ret;
-       struct evlist *evlist = evlist__new_default();
+       struct target target = {};
+       struct evlist *evlist = evlist__new_default(&target, /*sample_callchains=*/false);
 
        TEST_ASSERT_VAL("failed to get evlist", evlist);
 

diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index efbd9cd60c6305c972135547ca8e7bc79e97e484..c6e31ab8a6b8f748175e2ecaed67bea79e9188e6 100644 (file)
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -84,8 +84,11 @@ static int test__PERF_RECORD(struct test_suite *test __maybe_unused, int subtest
        CPU_ZERO_S(cpu_mask_size, cpu_mask);
 
        perf_sample__init(&sample, /*all=*/false);
-       if (evlist == NULL) /* Fallback for kernels lacking PERF_COUNT_SW_DUMMY */
-               evlist = evlist__new_default();
+       if (evlist == NULL) { /* Fallback for kernels lacking PERF_COUNT_SW_DUMMY */
+               struct target target = {};
+
+               evlist = evlist__new_default(&target, /*sample_callchains=*/false);
+       }
 
        if (evlist == NULL) {
                pr_debug("Not enough memory to create evlist\n");

diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c
index ec01150d208de798c565a6fd4156aec72b54c5b1..a34a7ab19a80c6bdc877a9f1f24d035d862387af 100644 (file)
--- a/tools/perf/tests/topology.c
+++ b/tools/perf/tests/topology.c
@@ -9,6 +9,7 @@
 #include "evlist.h"
 #include "debug.h"
 #include "pmus.h"
+#include "target.h"
 #include <linux/err.h>
 
 #define TEMPL "/tmp/perf-test-XXXXXX"
@@ -37,11 +38,12 @@ static int session_write_header(char *path)
                .path = path,
                .mode = PERF_DATA_MODE_WRITE,
        };
+       struct target target = {};
 
        session = perf_session__new(&data, NULL);
        TEST_ASSERT_VAL("can't get session", !IS_ERR(session));
 
-       session->evlist = evlist__new_default();
+       session->evlist = evlist__new_default(&target, /*sample_callchains=*/false);
        TEST_ASSERT_VAL("can't get evlist", session->evlist);
        session->evlist->session = session;
 

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 591bdf0b3e2a10623afd529706244105cc600c4d..c702741a917380b9c45c51576dc56fa3ebf97233 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -13,6 +13,7 @@
 #include "util/mmap.h"
 #include "thread_map.h"
 #include "target.h"
+#include "dwarf-regs.h"
 #include "evlist.h"
 #include "evsel.h"
 #include "record.h"
@@ -98,38 +99,47 @@ struct evlist *evlist__new(void)
        return evlist;
 }
 
-struct evlist *evlist__new_default(void)
+struct evlist *evlist__new_default(const struct target *target, bool sample_callchains)
 {
        struct evlist *evlist = evlist__new();
        bool can_profile_kernel;
        struct perf_pmu *pmu = NULL;
+       struct evsel *evsel;
+       char buf[256];
+       int err;
 
        if (!evlist)
                return NULL;
 
        can_profile_kernel = perf_event_paranoid_check(1);
 
-       while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
-               char buf[256];
-               int err;
-
-               snprintf(buf, sizeof(buf), "%s/cycles/%s", pmu->name,
+       if (EM_HOST == EM_S390 && sample_callchains) {
+               snprintf(buf, sizeof(buf), "software/%s/%s",
+                        target__has_cpu(target) ? "cpu-clock" : "task-clock",
                         can_profile_kernel ? "P" : "Pu");
                err = parse_event(evlist, buf);
-               if (err) {
-                       evlist__delete(evlist);
-                       return NULL;
+               if (err)
+                       goto out_err;
+       } else {
+               while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
+                       snprintf(buf, sizeof(buf), "%s/cycles/%s", pmu->name,
+                               can_profile_kernel ? "P" : "Pu");
+                       err = parse_event(evlist, buf);
+                       if (err)
+                               goto out_err;
                }
        }
 
+       /* If there is only 1 event a sample identifier isn't necessary. */
        if (evlist->core.nr_entries > 1) {
-               struct evsel *evsel;
-
                evlist__for_each_entry(evlist, evsel)
                        evsel__set_sample_id(evsel, /*can_sample_identifier=*/false);
        }
 
        return evlist;
+out_err:
+       evlist__delete(evlist);
+       return NULL;
 }
 
 struct evlist *evlist__new_dummy(void)

diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index d17c3b57a409c34d8b08f35def539ec627f16d19..e507f5f20ef61b9e0ad040695d93dd5143d10419 100644 (file)
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -104,7 +104,7 @@ struct evsel_str_handler {
 };
 
 struct evlist *evlist__new(void);
-struct evlist *evlist__new_default(void);
+struct evlist *evlist__new_default(const struct target *target, bool sample_callchains);
 struct evlist *evlist__new_dummy(void);
 void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
                  struct perf_thread_map *threads);

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 54c8922a8e473c08a30e8a4a574d3d3b03083113..5a294595a677620eb1866f94cb765c1911fd8afb 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1021,6 +1021,11 @@ static void __evsel__config_callchain(struct evsel *evsel, const struct record_o
        bool function = evsel__is_function_event(evsel);
        struct perf_event_attr *attr = &evsel->core.attr;
 
+       if (EM_HOST == EM_S390 && param->record_mode == CALLCHAIN_FP) {
+               pr_warning_once(
+                       "Framepointer unwinding lacks kernel support. Use '--call-graph dwarf'\n");
+       }
+
        evsel__set_sample_bit(evsel, CALLCHAIN);
 
        attr->sample_max_stack = param->max_stack;