[PATCH 02/20] selftest/powerpc/pmu: Add support for perf sampling tests
Kajol Jain
kjain at linux.ibm.com
Thu Jan 27 18:19:54 AEDT 2022
From: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
Add support functions for enabling perf sampling test in
a new folder "sampling_tests" under "selftests/powerpc/pmu".
This includes support functions for allocating and processing
the mmap buffer. These functions are added/defined in
"sampling_tests/misc.*" files.
Also updates the corresponding Makefiles in "selftests/powerpc"
and "sampling_tests" folder.
Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
---
tools/testing/selftests/powerpc/pmu/Makefile | 11 +-
.../powerpc/pmu/sampling_tests/Makefile | 20 ++++
.../powerpc/pmu/sampling_tests/misc.c | 105 ++++++++++++++++++
.../powerpc/pmu/sampling_tests/misc.h | 9 ++
4 files changed, 143 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
create mode 100644 tools/testing/selftests/powerpc/pmu/sampling_tests/misc.c
create mode 100644 tools/testing/selftests/powerpc/pmu/sampling_tests/misc.h
diff --git a/tools/testing/selftests/powerpc/pmu/Makefile b/tools/testing/selftests/powerpc/pmu/Makefile
index 904672fb78dd..edbd96d3b2ab 100644
--- a/tools/testing/selftests/powerpc/pmu/Makefile
+++ b/tools/testing/selftests/powerpc/pmu/Makefile
@@ -8,7 +8,7 @@ EXTRA_SOURCES := ../harness.c event.c lib.c ../utils.c
top_srcdir = ../../../../..
include ../../lib.mk
-all: $(TEST_GEN_PROGS) ebb
+all: $(TEST_GEN_PROGS) ebb sampling_tests
$(TEST_GEN_PROGS): $(EXTRA_SOURCES)
@@ -26,25 +26,32 @@ DEFAULT_RUN_TESTS := $(RUN_TESTS)
override define RUN_TESTS
$(DEFAULT_RUN_TESTS)
TARGET=ebb; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET run_tests
+ TARGET=sampling_tests; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET run_tests
endef
DEFAULT_EMIT_TESTS := $(EMIT_TESTS)
override define EMIT_TESTS
$(DEFAULT_EMIT_TESTS)
TARGET=ebb; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -s -C $$TARGET emit_tests
+ TARGET=sampling_tests; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -s -C $$TARGET emit_tests
endef
DEFAULT_INSTALL_RULE := $(INSTALL_RULE)
override define INSTALL_RULE
$(DEFAULT_INSTALL_RULE)
TARGET=ebb; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET install
+ TARGET=sampling_tests; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET install
endef
clean:
$(RM) $(TEST_GEN_PROGS) $(OUTPUT)/loop.o
TARGET=ebb; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean
+ TARGET=sampling_tests; BUILD_TARGET=$$OUTPUT/$$TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean
ebb:
TARGET=$@; BUILD_TARGET=$$OUTPUT/$$TARGET; mkdir -p $$BUILD_TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -k -C $$TARGET all
-.PHONY: all run_tests clean ebb
+sampling_tests:
+ TARGET=$@; BUILD_TARGET=$$OUTPUT/$$TARGET; mkdir -p $$BUILD_TARGET; $(MAKE) OUTPUT=$$BUILD_TARGET -k -C $$TARGET all
+
+.PHONY: all run_tests clean ebb sampling_tests
diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
new file mode 100644
index 000000000000..eb00c9f931ec
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+include ../../../../../../scripts/Kbuild.include
+
+all: $(TEST_GEN_PROGS)
+
+noarg:
+ $(MAKE) -C ../../
+
+CFLAGS += -m64 -I../../../../../lib/
+
+# Toolchains may build PIE by default which breaks the assembly
+no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \
+ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -no-pie -x c - -o "$$TMP", -no-pie)
+
+LDFLAGS += $(no-pie-option)
+
+top_srcdir = ../../../../../..
+include ../../../lib.mk
+
+$(TEST_GEN_PROGS): ../../harness.c ../../utils.c ../event.c ../lib.c misc.c misc.h
diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/misc.c b/tools/testing/selftests/powerpc/pmu/sampling_tests/misc.c
new file mode 100644
index 000000000000..4779b107f43b
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/misc.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022, Athira Rajeev, IBM Corp.
+ */
+
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+#include "misc.h"
+
+#define PAGE_SIZE sysconf(_SC_PAGESIZE)
+
+/*
+ * Allocate mmap buffer of "mmap_pages" number of
+ * pages.
+ */
+void *event_sample_buf_mmap(int fd, int mmap_pages)
+{
+ size_t page_size = sysconf(_SC_PAGESIZE);
+ size_t mmap_size;
+ void *buff;
+
+ if (mmap_pages <= 0)
+ return NULL;
+
+ if (fd <= 0)
+ return NULL;
+
+ mmap_size = page_size * (1 + mmap_pages);
+ buff = mmap(NULL, mmap_size,
+ PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+
+ if (buff == MAP_FAILED) {
+ perror("mmap() failed.");
+ return NULL;
+ }
+ return buff;
+}
+
+/*
+ * Post process the mmap buffer.
+ * - If sample_count != NULL then return count of total
+ * number of samples present in the mmap buffer.
+ * - If sample_count == NULL then return the address
+ * of first sample from the mmap buffer
+ */
+void *__event_read_samples(void *sample_buff, size_t *size, u64 *sample_count)
+{
+ size_t page_size = sysconf(_SC_PAGESIZE);
+ struct perf_event_header *header = sample_buff + page_size;
+ struct perf_event_mmap_page *metadata_page = sample_buff;
+ unsigned long data_head, data_tail;
+
+ /*
+ * PERF_RECORD_SAMPLE:
+ * struct {
+ * struct perf_event_header hdr;
+ * u64 data[];
+ * };
+ */
+
+ data_head = metadata_page->data_head;
+ /* sync memory before reading sample */
+ mb();
+ data_tail = metadata_page->data_tail;
+
+ /* Check for sample_count */
+ if (sample_count)
+ *sample_count = 0;
+
+ while (1) {
+ /*
+ * Reads the mmap data buffer by moving
+ * the data_tail to know the last read data.
+ * data_head points to head in data buffer.
+ * refer "struct perf_event_mmap_page" in
+ * "include/uapi/linux/perf_event.h".
+ */
+ if (data_head - data_tail < sizeof(header))
+ return NULL;
+
+ data_tail += sizeof(header);
+ if (header->type == PERF_RECORD_SAMPLE) {
+ *size = (header->size - sizeof(header));
+ if (!sample_count)
+ return sample_buff + page_size + data_tail;
+ data_tail += *size;
+ *sample_count += 1;
+ } else {
+ *size = (header->size - sizeof(header));
+ if ((metadata_page->data_tail + *size) > metadata_page->data_head)
+ data_tail = metadata_page->data_head;
+ else
+ data_tail += *size;
+ }
+ header = (struct perf_event_header *)((void *)header + header->size);
+ }
+ return NULL;
+}
diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/misc.h b/tools/testing/selftests/powerpc/pmu/sampling_tests/misc.h
new file mode 100644
index 000000000000..291f9adba817
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/misc.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2022, Athira Rajeev, IBM Corp.
+ */
+
+#include "../event.h"
+
+void *event_sample_buf_mmap(int fd, int mmap_pages);
+void *__event_read_samples(void *sample_buff, size_t *size, u64 *sample_count);
--
2.27.0
More information about the Linuxppc-dev
mailing list