[PATCH mm-unstable v1 01/20] selftests/vm: anon_cow: prepare for non-anonymous COW tests

David Hildenbrand
2022-11-16T10:29:05Z

Originally, the plan was to have a separate tests for testing COW of
non-anonymous (e.g., shared zeropage) pages.

Turns out, that we'd need a lot of similar functionality and that there
isn't a really good reason to separate it. So let's prepare for non-anon
tests by renaming to "cow".

Signed-off-by: David Hildenbrand <david@redhat.com>
---
tools/testing/selftests/vm/.gitignore | 2 +-
tools/testing/selftests/vm/Makefile | 10 ++++----
tools/testing/selftests/vm/check_config.sh | 4 +--
.../selftests/vm/{anon_cow.c => cow.c} | 25 +++++++++++--------
tools/testing/selftests/vm/run_vmtests.sh | 8 +++---
5 files changed, 27 insertions(+), 22 deletions(-)
rename tools/testing/selftests/vm/{anon_cow.c => cow.c} (97%)

diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore
index 8a536c731e3c..ee8c41c998e6 100644
--- a/tools/testing/selftests/vm/.gitignore
+++ b/tools/testing/selftests/vm/.gitignore
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-anon_cow
+cow
hugepage-mmap
hugepage-mremap
hugepage-shm
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 0986bd60c19f..89c14e41bd43 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -27,7 +27,7 @@ MAKEFLAGS += --no-builtin-rules

CFLAGS = -Wall -I $(top_srcdir) -I $(top_srcdir)/usr/include $(EXTRA_CFLAGS) $(KHDR_INCLUDES)
LDLIBS = -lrt -lpthread
-TEST_GEN_FILES = anon_cow
+TEST_GEN_FILES = cow
TEST_GEN_FILES += compaction_test
TEST_GEN_FILES += gup_test
TEST_GEN_FILES += hmm-tests
@@ -99,7 +99,7 @@ TEST_FILES += va_128TBswitch.sh

include ../lib.mk

-$(OUTPUT)/anon_cow: vm_util.c
+$(OUTPUT)/cow: vm_util.c
$(OUTPUT)/khugepaged: vm_util.c
$(OUTPUT)/ksm_functional_tests: vm_util.c
$(OUTPUT)/madv_populate: vm_util.c
@@ -156,8 +156,8 @@ warn_32bit_failure:
endif
endif

-# ANON_COW_EXTRA_LIBS may get set in local_config.mk, or it may be left empty.
-$(OUTPUT)/anon_cow: LDLIBS += $(ANON_COW_EXTRA_LIBS)
+# cow_EXTRA_LIBS may get set in local_config.mk, or it may be left empty.
+$(OUTPUT)/cow: LDLIBS += $(COW_EXTRA_LIBS)

$(OUTPUT)/mlock-random-test $(OUTPUT)/memfd_secret: LDLIBS += -lcap

@@ -170,7 +170,7 @@ local_config.mk local_config.h: check_config.sh

EXTRA_CLEAN += local_config.mk local_config.h

-ifeq ($(ANON_COW_EXTRA_LIBS),)
+ifeq ($(COW_EXTRA_LIBS),)
all: warn_missing_liburing

warn_missing_liburing:
diff --git a/tools/testing/selftests/vm/check_config.sh b/tools/testing/selftests/vm/check_config.sh
index 9a44c6520925..bcba3af0acea 100644
--- a/tools/testing/selftests/vm/check_config.sh
+++ b/tools/testing/selftests/vm/check_config.sh
@@ -21,11 +21,11 @@ $CC -c $tmpfile_c -o $tmpfile_o >/dev/null 2>&1

if [ -f $tmpfile_o ]; then
echo "#define LOCAL_CONFIG_HAVE_LIBURING 1" > $OUTPUT_H_FILE
- echo "ANON_COW_EXTRA_LIBS = -luring" > $OUTPUT_MKFILE
+ echo "COW_EXTRA_LIBS = -luring" > $OUTPUT_MKFILE
else
echo "// No liburing support found" > $OUTPUT_H_FILE
echo "# No liburing support found, so:" > $OUTPUT_MKFILE
- echo "ANON_COW_EXTRA_LIBS = " >> $OUTPUT_MKFILE
+ echo "COW_EXTRA_LIBS = " >> $OUTPUT_MKFILE
fi

rm ${tmpname}.*
diff --git a/tools/testing/selftests/vm/anon_cow.c b/tools/testing/selftests/vm/cow.c
similarity index 97%
rename from tools/testing/selftests/vm/anon_cow.c
rename to tools/testing/selftests/vm/cow.c
index bbb251eb5025..d202bfd63585 100644
--- a/tools/testing/selftests/vm/anon_cow.c
+++ b/tools/testing/selftests/vm/cow.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * COW (Copy On Write) tests for anonymous memory.
+ * COW (Copy On Write) tests.
*
* Copyright 2022, Red Hat, Inc.
*
@@ -986,7 +986,11 @@ struct test_case {
test_fn fn;
};

-static const struct test_case test_cases[] = {
+/*
+ * Test cases that are specific to anonymous pages: pages in private mappings
+ * that may get shared via COW during fork().
+ */
+static const struct test_case anon_test_cases[] = {
/*
* Basic COW tests for fork() without any GUP. If we miss to break COW,
* either the child can observe modifications by the parent or the
@@ -1104,7 +1108,7 @@ static const struct test_case test_cases[] = {
},
};

-static void run_test_case(struct test_case const *test_case)
+static void run_anon_test_case(struct test_case const *test_case)
{
int i;

@@ -1125,15 +1129,17 @@ static void run_test_case(struct test_case const *test_case)
hugetlbsizes[i]);
}

-static void run_test_cases(void)
+static void run_anon_test_cases(void)
{
int i;

- for (i = 0; i < ARRAY_SIZE(test_cases); i++)
- run_test_case(&test_cases[i]);
+ ksft_print_msg("[INFO] Anonymous memory tests in private mappings\n");
+
+ for (i = 0; i < ARRAY_SIZE(anon_test_cases); i++)
+ run_anon_test_case(&anon_test_cases[i]);
}

-static int tests_per_test_case(void)
+static int tests_per_anon_test_case(void)
{
int tests = 2 + nr_hugetlbsizes;

@@ -1144,7 +1150,6 @@ static int tests_per_test_case(void)

int main(int argc, char **argv)
{
- int nr_test_cases = ARRAY_SIZE(test_cases);
int err;

pagesize = getpagesize();
@@ -1152,14 +1157,14 @@ int main(int argc, char **argv)
detect_hugetlbsizes();

ksft_print_header();
- ksft_set_plan(nr_test_cases * tests_per_test_case());
+ ksft_set_plan(ARRAY_SIZE(anon_test_cases) * tests_per_anon_test_case());

gup_fd = open("/sys/kernel/debug/gup_test", O_RDWR);
pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
if (pagemap_fd < 0)
ksft_exit_fail_msg("opening pagemap failed\n");

- run_test_cases();
+ run_anon_test_cases();

err = ksft_get_fail_cnt();
if (err)
diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
index ce52e4f5ff21..71744b9002d0 100755
--- a/tools/testing/selftests/vm/run_vmtests.sh
+++ b/tools/testing/selftests/vm/run_vmtests.sh
@@ -50,8 +50,8 @@ separated by spaces:
memory protection key tests
- soft_dirty
test soft dirty page bit semantics
-- anon_cow
- test anonymous copy-on-write semantics
+- cow
+ test copy-on-write semantics
example: ./run_vmtests.sh -t "hmm mmap ksm"
EOF
exit 0
@@ -267,7 +267,7 @@ fi

CATEGORY="soft_dirty" run_test ./soft-dirty

-# COW tests for anonymous memory
-CATEGORY="anon_cow" run_test ./anon_cow
+# COW tests
+CATEGORY="cow" run_test ./cow

exit $exitcode
--
2.38.1