* [PATCH 2/3] selftests: Add support files for powerpc tests
2013-07-31 4:56 [PATCH 1/3] selftests: Add infrastructure for powerpc selftests Michael Ellerman
@ 2013-07-31 4:56 ` Michael Ellerman
2013-07-31 6:23 ` Michael Ellerman
2013-07-31 6:52 ` [PATCH v2] " Michael Ellerman
2013-07-31 4:56 ` [PATCH 3/3] selftests: Add test of PMU instruction counting on powerpc Michael Ellerman
1 sibling, 2 replies; 5+ messages in thread
From: Michael Ellerman @ 2013-07-31 4:56 UTC (permalink / raw)
To: linuxppc-dev
Cc: Jeremy Kerr, Andrew Morton, Michael Neuling, linux-kernel,
Anton Blanchard
This commit adds support code used by upcoming powerpc tests.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
tools/testing/selftests/powerpc/harness.c | 83 +++++++++++++++++++++++++++++++
tools/testing/selftests/powerpc/subunit.h | 47 +++++++++++++++++
tools/testing/selftests/powerpc/utils.h | 34 +++++++++++++
3 files changed, 164 insertions(+)
create mode 100644 tools/testing/selftests/powerpc/harness.c
create mode 100644 tools/testing/selftests/powerpc/subunit.h
create mode 100644 tools/testing/selftests/powerpc/utils.h
diff --git a/tools/testing/selftests/powerpc/harness.c b/tools/testing/selftests/powerpc/harness.c
new file mode 100644
index 0000000..ad73a34
--- /dev/null
+++ b/tools/testing/selftests/powerpc/harness.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "subunit.h"
+#include "utils.h"
+
+#define TIMEOUT 120
+#define KILL_TIMEOUT 5
+
+
+int run_test(int (test_function)(void), char *name)
+{
+ bool terminated;
+ int rc, status;
+ pid_t pid;
+
+ /* Make sure output is flushed before forking */
+ fflush(stdout);
+
+ pid = fork();
+ if (pid == 0) {
+ exit(test_function());
+ } else if (pid == -1) {
+ perror("fork");
+ return 1;
+ }
+
+ /* Wake us up in timeout seconds */
+ alarm(TIMEOUT);
+ terminated = false;
+
+wait:
+ rc = waitpid(pid, &status, 0);
+ if (rc == -1) {
+ if (errno != EINTR) {
+ printf("unknown error from waitpid\n");
+ return 1;
+ }
+
+ if (terminated) {
+ printf("!! force killing %s\n", name);
+ kill(pid, SIGKILL);
+ return 1;
+ } else {
+ printf("!! killing %s\n", name);
+ kill(pid, SIGTERM);
+ terminated = true;
+ alarm(KILL_TIMEOUT);
+ goto wait;
+ }
+ }
+
+ if (WIFEXITED(status))
+ status = WEXITSTATUS(status);
+ else
+ status = 1; /* Signal or other */
+
+ return status;
+}
+
+int test_harness(int (test_function)(void), char *name)
+{
+ int rc;
+
+ test_start(name);
+ test_set_git_version(GIT_VERSION);
+
+ rc = run_test(test_function, name);
+
+ test_finish(name, rc);
+
+ return rc;
+}
diff --git a/tools/testing/selftests/powerpc/subunit.h b/tools/testing/selftests/powerpc/subunit.h
new file mode 100644
index 0000000..98a2292
--- /dev/null
+++ b/tools/testing/selftests/powerpc/subunit.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#ifndef _SELFTESTS_POWERPC_SUBUNIT_H
+#define _SELFTESTS_POWERPC_SUBUNIT_H
+
+static inline void test_start(char *name)
+{
+ printf("test: %s\n", name);
+}
+
+static inline void test_failure_detail(char *name, char *detail)
+{
+ printf("failure: %s [%s]\n", name, detail);
+}
+
+static inline void test_failure(char *name)
+{
+ printf("failure: %s\n", name);
+}
+
+static inline void test_error(char *name)
+{
+ printf("error: %s\n", name);
+}
+
+static inline void test_success(char *name)
+{
+ printf("success: %s\n", name);
+}
+
+static inline void test_finish(char *name, int status)
+{
+ if (status)
+ test_failure(name);
+ else
+ test_success(name);
+}
+
+static inline void test_set_git_version(char *value)
+{
+ printf("tags: git_version:%s\n", value);
+}
+
+#endif /* _SELFTESTS_POWERPC_SUBUNIT_H */
diff --git a/tools/testing/selftests/powerpc/utils.h b/tools/testing/selftests/powerpc/utils.h
new file mode 100644
index 0000000..5851c4b
--- /dev/null
+++ b/tools/testing/selftests/powerpc/utils.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#ifndef _SELFTESTS_POWERPC_UTILS_H
+#define _SELFTESTS_POWERPC_UTILS_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* Avoid headaches with PRI?64 - just use %ll? always */
+typedef unsigned long long u64;
+typedef signed long long s64;
+
+/* Just for familiarity */
+typedef uint32_t u32;
+typedef uint8_t u8;
+
+
+int test_harness(int (test_function)(void), char *name);
+
+
+/* Yes, this is evil */
+#define FAIL_IF(x) \
+do { \
+ if ((x)) { \
+ fprintf(stderr, \
+ "[FAIL] Test FAILED on line %d\n", __LINE__); \
+ return 1; \
+ } \
+} while (0)
+
+#endif /* _SELFTESTS_POWERPC_UTILS_H */
--
1.8.1.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] selftests: Add test of PMU instruction counting on powerpc
2013-07-31 4:56 [PATCH 1/3] selftests: Add infrastructure for powerpc selftests Michael Ellerman
2013-07-31 4:56 ` [PATCH 2/3] selftests: Add support files for powerpc tests Michael Ellerman
@ 2013-07-31 4:56 ` Michael Ellerman
1 sibling, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2013-07-31 4:56 UTC (permalink / raw)
To: linuxppc-dev
Cc: Jeremy Kerr, Andrew Morton, Michael Neuling, linux-kernel,
Anton Blanchard
This commit adds a test of instruction counting using the PMU on powerpc.
Although the bulk of the code is architecture agnostic, the code needs to
run a precisely sized loop which is implemented in assembler.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
tools/testing/selftests/powerpc/Makefile | 2 +-
tools/testing/selftests/powerpc/pmu/Makefile | 23 ++++
.../selftests/powerpc/pmu/count_instructions.c | 135 +++++++++++++++++++++
tools/testing/selftests/powerpc/pmu/event.c | 105 ++++++++++++++++
tools/testing/selftests/powerpc/pmu/event.h | 39 ++++++
tools/testing/selftests/powerpc/pmu/loop.S | 46 +++++++
6 files changed, 349 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/pmu/Makefile
create mode 100644 tools/testing/selftests/powerpc/pmu/count_instructions.c
create mode 100644 tools/testing/selftests/powerpc/pmu/event.c
create mode 100644 tools/testing/selftests/powerpc/pmu/event.h
create mode 100644 tools/testing/selftests/powerpc/pmu/loop.S
diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index bade865..7cb4744 100644
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -13,7 +13,7 @@ CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CUR
export CC CFLAGS
-TARGETS =
+TARGETS = pmu
endif
diff --git a/tools/testing/selftests/powerpc/pmu/Makefile b/tools/testing/selftests/powerpc/pmu/Makefile
new file mode 100644
index 0000000..7216f00
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/Makefile
@@ -0,0 +1,23 @@
+noarg:
+ $(MAKE) -C ../
+
+PROGS := count_instructions
+EXTRA_SOURCES := ../harness.c event.c
+
+all: $(PROGS)
+
+$(PROGS): $(EXTRA_SOURCES)
+
+# loop.S can only be built 64-bit
+count_instructions: loop.S count_instructions.c $(EXTRA_SOURCES)
+ $(CC) $(CFLAGS) -m64 -o $@ $^
+
+run_tests: all
+ @-for PROG in $(PROGS); do \
+ ./$$PROG; \
+ done;
+
+clean:
+ rm -f $(PROGS) loop.o
+
+.PHONY: all run_tests clean
diff --git a/tools/testing/selftests/powerpc/pmu/count_instructions.c b/tools/testing/selftests/powerpc/pmu/count_instructions.c
new file mode 100644
index 0000000..312b4f0
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/count_instructions.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/prctl.h>
+
+#include "event.h"
+#include "utils.h"
+
+extern void thirty_two_instruction_loop(u64 loops);
+
+static void setup_event(struct event *e, u64 config, char *name)
+{
+ event_init_opts(e, config, PERF_TYPE_HARDWARE, name);
+
+ e->attr.disabled = 1;
+ e->attr.exclude_kernel = 1;
+ e->attr.exclude_hv = 1;
+ e->attr.exclude_idle = 1;
+}
+
+static int do_count_loop(struct event *events, u64 instructions,
+ u64 overhead, bool report)
+{
+ s64 difference, expected;
+ double percentage;
+
+ prctl(PR_TASK_PERF_EVENTS_ENABLE);
+
+ /* Run for 1M instructions */
+ thirty_two_instruction_loop(instructions >> 5);
+
+ prctl(PR_TASK_PERF_EVENTS_DISABLE);
+
+ event_read(&events[0]);
+ event_read(&events[1]);
+
+ expected = instructions + overhead;
+ difference = events[0].result.value - expected;
+ percentage = (double)difference / events[0].result.value * 100;
+
+ if (report) {
+ event_report(&events[0]);
+ event_report(&events[1]);
+
+ printf("Looped for %llu instructions, overhead %llu\n", instructions, overhead);
+ printf("Expected %llu\n", expected);
+ printf("Actual %llu\n", events[0].result.value);
+ printf("Delta %lld, %f%%\n", difference, percentage);
+ }
+
+ event_reset(&events[0]);
+ event_reset(&events[1]);
+
+ if (difference < 0)
+ difference = -difference;
+
+ /* Tolerate a difference below 0.0001 % */
+ difference *= 10000 * 100;
+ if (difference / events[0].result.value)
+ return -1;
+
+ return 0;
+}
+
+/* Count how many instructions it takes to do a null loop */
+static u64 determine_overhead(struct event *events)
+{
+ u64 current, overhead;
+ int i;
+
+ do_count_loop(events, 0, 0, false);
+ overhead = events[0].result.value;
+
+ for (i = 0; i < 100; i++) {
+ do_count_loop(events, 0, 0, false);
+ current = events[0].result.value;
+ if (current < overhead) {
+ printf("Replacing overhead %llu with %llu\n", overhead, current);
+ overhead = current;
+ }
+ }
+
+ return overhead;
+}
+
+static int count_instructions(void)
+{
+ struct event events[2];
+ u64 overhead;
+
+ setup_event(&events[0], PERF_COUNT_HW_INSTRUCTIONS, "instructions");
+ setup_event(&events[1], PERF_COUNT_HW_CPU_CYCLES, "cycles");
+
+ if (event_open(&events[0])) {
+ perror("perf_event_open");
+ return -1;
+ }
+
+ if (event_open_with_group(&events[1], events[0].fd)) {
+ perror("perf_event_open");
+ return -1;
+ }
+
+ overhead = determine_overhead(events);
+ printf("Overhead of null loop: %llu instructions\n", overhead);
+
+ /* Run for 1M instructions */
+ FAIL_IF(do_count_loop(events, 0x100000, overhead, true));
+
+ /* Run for 10M instructions */
+ FAIL_IF(do_count_loop(events, 0xa00000, overhead, true));
+
+ /* Run for 100M instructions */
+ FAIL_IF(do_count_loop(events, 0x6400000, overhead, true));
+
+ /* Run for 1G instructions */
+ FAIL_IF(do_count_loop(events, 0x40000000, overhead, true));
+
+ event_close(&events[0]);
+ event_close(&events[1]);
+
+ return 0;
+}
+
+int main(void)
+{
+ return test_harness(count_instructions, "count_instructions");
+}
diff --git a/tools/testing/selftests/powerpc/pmu/event.c b/tools/testing/selftests/powerpc/pmu/event.c
new file mode 100644
index 0000000..2b2d11d
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/event.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+
+#include "event.h"
+
+
+int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
+ int group_fd, unsigned long flags)
+{
+ return syscall(__NR_perf_event_open, attr, pid, cpu,
+ group_fd, flags);
+}
+
+void event_init_opts(struct event *e, u64 config, int type, char *name)
+{
+ memset(e, 0, sizeof(*e));
+
+ e->name = name;
+
+ e->attr.type = type;
+ e->attr.config = config;
+ e->attr.size = sizeof(e->attr);
+ /* This has to match the structure layout in the header */
+ e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
+ PERF_FORMAT_TOTAL_TIME_RUNNING;
+}
+
+void event_init_named(struct event *e, u64 config, char *name)
+{
+ event_init_opts(e, config, PERF_TYPE_RAW, name);
+}
+
+#define PERF_CURRENT_PID 0
+#define PERF_NO_CPU -1
+#define PERF_NO_GROUP -1
+
+int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd)
+{
+ e->fd = perf_event_open(&e->attr, pid, cpu, group_fd, 0);
+ if (e->fd == -1) {
+ perror("perf_event_open");
+ return -1;
+ }
+
+ return 0;
+}
+
+int event_open_with_group(struct event *e, int group_fd)
+{
+ return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, group_fd);
+}
+
+int event_open(struct event *e)
+{
+ return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, PERF_NO_GROUP);
+}
+
+void event_close(struct event *e)
+{
+ close(e->fd);
+}
+
+int event_reset(struct event *e)
+{
+ return ioctl(e->fd, PERF_EVENT_IOC_RESET);
+}
+
+int event_read(struct event *e)
+{
+ int rc;
+
+ rc = read(e->fd, &e->result, sizeof(e->result));
+ if (rc != sizeof(e->result)) {
+ fprintf(stderr, "read error on event %p!\n", e);
+ return -1;
+ }
+
+ return 0;
+}
+
+void event_report_justified(struct event *e, int name_width, int result_width)
+{
+ printf("%*s: result %*llu ", name_width, e->name, result_width,
+ e->result.value);
+
+ if (e->result.running == e->result.enabled)
+ printf("running/enabled %llu\n", e->result.running);
+ else
+ printf("running %llu enabled %llu\n", e->result.running,
+ e->result.enabled);
+}
+
+void event_report(struct event *e)
+{
+ event_report_justified(e, 0, 0);
+}
diff --git a/tools/testing/selftests/powerpc/pmu/event.h b/tools/testing/selftests/powerpc/pmu/event.h
new file mode 100644
index 0000000..e699319
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/event.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#ifndef _SELFTESTS_POWERPC_PMU_EVENT_H
+#define _SELFTESTS_POWERPC_PMU_EVENT_H
+
+#include <unistd.h>
+#include <linux/perf_event.h>
+
+#include "utils.h"
+
+
+struct event {
+ struct perf_event_attr attr;
+ char *name;
+ int fd;
+ /* This must match the read_format we use */
+ struct {
+ u64 value;
+ u64 running;
+ u64 enabled;
+ } result;
+};
+
+void event_init(struct event *e, u64 config);
+void event_init_named(struct event *e, u64 config, char *name);
+void event_init_opts(struct event *e, u64 config, int type, char *name);
+int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd);
+int event_open_with_group(struct event *e, int group_fd);
+int event_open(struct event *e);
+void event_close(struct event *e);
+int event_reset(struct event *e);
+int event_read(struct event *e);
+void event_report_justified(struct event *e, int name_width, int result_width);
+void event_report(struct event *e);
+
+#endif /* _SELFTESTS_POWERPC_PMU_EVENT_H */
diff --git a/tools/testing/selftests/powerpc/pmu/loop.S b/tools/testing/selftests/powerpc/pmu/loop.S
new file mode 100644
index 0000000..8820e3d
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/loop.S
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2013, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+ .text
+
+ .global thirty_two_instruction_loop
+ .type .thirty_two_instruction_loop,@function
+ .section ".opd","aw",@progbits
+thirty_two_instruction_loop:
+ .quad .thirty_two_instruction_loop, .TOC.@tocbase, 0
+ .previous
+.thirty_two_instruction_loop:
+ cmpwi %r3,0
+ beqlr
+ addi %r4,%r3,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1
+ addi %r4,%r4,1 # 28 addi's
+ subi %r3,%r3,1
+ b .thirty_two_instruction_loop
--
1.8.1.2
^ permalink raw reply related [flat|nested] 5+ messages in thread