perf kwork: New tool to trace time properties of kernel work (such as softirq, and workqueue)

The 'perf kwork' tool is used to trace time properties of kernel work
(such as irq, softirq, and workqueue), including runtime, latency, and
timehist, using the infrastructure in the perf tools to allow tracing
extra targets.

This is the first commit to reuse the 'perf record' framework code to
implement a simple record function, kwork is not supported currently.

Test cases:

  # perf

   usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

   The most commonly used perf commands are:
  <SNIP>
     iostat          Show I/O performance metrics
     kallsyms        Searches running kernel for symbols
     kmem            Tool to trace/measure kernel memory properties
     kvm             Tool to trace/measure kvm guest os
     kwork           Tool to trace/measure kernel work properties (latencies)
     list            List all symbolic event types
     lock            Analyze lock events
     mem             Profile memory accesses
     record          Run a command and record its profile into perf.data
  <SNIP>
   See 'perf help COMMAND' for more information on a specific command.

  # perf kwork

   Usage: perf kwork [<options>] {record}

      -D, --dump-raw-trace  dump raw trace in ASCII
      -f, --force           don't complain, do it
      -k, --kwork <kwork>   list of kwork to profile
      -v, --verbose         be more verbose (show symbol address, etc)

  # perf kwork record -- sleep 1
  [ perf record: Woken up 0 times to write data ]
  [ perf record: Captured and wrote 1.787 MB perf.data ]

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220709015033.38326-2-yangjihong1@huawei.com
[ Add {} for multiline if blocks ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/tools/perf/builtin-kwork.c b/tools/perf/builtin-kwork.c
new file mode 100644
index 000000000000..3e8d5fa47674
--- /dev/null
+++ b/tools/perf/builtin-kwork.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * builtin-kwork.c
+ *
+ * Copyright (c) 2022  Huawei Inc,  Yang Jihong <yangjihong1@huawei.com>
+ */
+
+#include "builtin.h"
+
+#include "util/data.h"
+#include "util/kwork.h"
+#include "util/debug.h"
+#include "util/symbol.h"
+#include "util/thread.h"
+#include "util/string2.h"
+#include "util/callchain.h"
+#include "util/evsel_fprintf.h"
+
+#include <subcmd/pager.h>
+#include <subcmd/parse-options.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/err.h>
+#include <linux/time64.h>
+#include <linux/zalloc.h>
+
+static struct kwork_class *kwork_class_supported_list[KWORK_CLASS_MAX] = {
+};
+
+static void setup_event_list(struct perf_kwork *kwork,
+			     const struct option *options,
+			     const char * const usage_msg[])
+{
+	int i;
+	struct kwork_class *class;
+	char *tmp, *tok, *str;
+
+	if (kwork->event_list_str == NULL)
+		goto null_event_list_str;
+
+	str = strdup(kwork->event_list_str);
+	for (tok = strtok_r(str, ", ", &tmp);
+	     tok; tok = strtok_r(NULL, ", ", &tmp)) {
+		for (i = 0; i < KWORK_CLASS_MAX; i++) {
+			class = kwork_class_supported_list[i];
+			if (strcmp(tok, class->name) == 0) {
+				list_add_tail(&class->list, &kwork->class_list);
+				break;
+			}
+		}
+		if (i == KWORK_CLASS_MAX) {
+			usage_with_options_msg(usage_msg, options,
+					       "Unknown --event key: `%s'", tok);
+		}
+	}
+	free(str);
+
+null_event_list_str:
+	/*
+	 * config all kwork events if not specified
+	 */
+	if (list_empty(&kwork->class_list)) {
+		for (i = 0; i < KWORK_CLASS_MAX; i++) {
+			list_add_tail(&kwork_class_supported_list[i]->list,
+				      &kwork->class_list);
+		}
+	}
+
+	pr_debug("Config event list:");
+	list_for_each_entry(class, &kwork->class_list, list)
+		pr_debug(" %s", class->name);
+	pr_debug("\n");
+}
+
+static int perf_kwork__record(struct perf_kwork *kwork,
+			      int argc, const char **argv)
+{
+	const char **rec_argv;
+	unsigned int rec_argc, i, j;
+	struct kwork_class *class;
+
+	const char *const record_args[] = {
+		"record",
+		"-a",
+		"-R",
+		"-m", "1024",
+		"-c", "1",
+	};
+
+	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
+
+	list_for_each_entry(class, &kwork->class_list, list)
+		rec_argc += 2 * class->nr_tracepoints;
+
+	rec_argv = calloc(rec_argc + 1, sizeof(char *));
+	if (rec_argv == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(record_args); i++)
+		rec_argv[i] = strdup(record_args[i]);
+
+	list_for_each_entry(class, &kwork->class_list, list) {
+		for (j = 0; j < class->nr_tracepoints; j++) {
+			rec_argv[i++] = strdup("-e");
+			rec_argv[i++] = strdup(class->tp_handlers[j].name);
+		}
+	}
+
+	for (j = 1; j < (unsigned int)argc; j++, i++)
+		rec_argv[i] = argv[j];
+
+	BUG_ON(i != rec_argc);
+
+	pr_debug("record comm: ");
+	for (j = 0; j < rec_argc; j++)
+		pr_debug("%s ", rec_argv[j]);
+	pr_debug("\n");
+
+	return cmd_record(i, rec_argv);
+}
+
+int cmd_kwork(int argc, const char **argv)
+{
+	static struct perf_kwork kwork = {
+		.class_list          = LIST_HEAD_INIT(kwork.class_list),
+		.force               = false,
+		.event_list_str      = NULL,
+	};
+	const struct option kwork_options[] = {
+	OPT_INCR('v', "verbose", &verbose,
+		 "be more verbose (show symbol address, etc)"),
+	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
+		    "dump raw trace in ASCII"),
+	OPT_STRING('k', "kwork", &kwork.event_list_str, "kwork",
+		   "list of kwork to profile"),
+	OPT_BOOLEAN('f', "force", &kwork.force, "don't complain, do it"),
+	OPT_END()
+	};
+	const char *kwork_usage[] = {
+		NULL,
+		NULL
+	};
+	const char *const kwork_subcommands[] = {
+		"record", NULL
+	};
+
+	argc = parse_options_subcommand(argc, argv, kwork_options,
+					kwork_subcommands, kwork_usage,
+					PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc)
+		usage_with_options(kwork_usage, kwork_options);
+
+	setup_event_list(&kwork, kwork_options, kwork_usage);
+
+	if (strlen(argv[0]) > 2 && strstarts("record", argv[0]))
+		return perf_kwork__record(&kwork, argc, argv);
+	else
+		usage_with_options(kwork_usage, kwork_options);
+
+	return 0;
+}