The testing is done by ensuring that the fragment allocated
from a frag_frag_cache instance is pushed into a ptr_ring
instance in a kthread binded to a specified cpu, and a kthread
binded to a specified cpu will pop the fragment from the
ptr_ring and free the fragment.
CC: Alexander Duyck <alexander.duyck@xxxxxxxxx>
Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
tools/testing/selftests/mm/Makefile | 2 +
tools/testing/selftests/mm/page_frag/Makefile | 18 ++
.../selftests/mm/page_frag/page_frag_test.c | 170 ++++++++++++++++++
tools/testing/selftests/mm/run_vmtests.sh | 9 +-
4 files changed, 198 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/mm/page_frag/Makefile
create mode 100644 tools/testing/selftests/mm/page_frag/page_frag_test.c
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index cfad627e8d94..ed196901b9ca 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -36,6 +36,8 @@ MAKEFLAGS += --no-builtin-rules
CFLAGS = -Wall -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
LDLIBS = -lrt -lpthread -lm
+TEST_GEN_MODS_DIR := page_frag
+
TEST_GEN_FILES = cow
TEST_GEN_FILES += compaction_test
TEST_GEN_FILES += gup_longterm
diff --git a/tools/testing/selftests/mm/page_frag/Makefile b/tools/testing/selftests/mm/page_frag/Makefile
new file mode 100644
index 000000000000..58dda74d50a3
--- /dev/null
+++ b/tools/testing/selftests/mm/page_frag/Makefile
@@ -0,0 +1,18 @@
+PAGE_FRAG_TEST_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
+KDIR ?= $(abspath $(PAGE_FRAG_TEST_DIR)/../../../../..)
+
+ifeq ($(V),1)
+Q =
+else
+Q = @
+endif
+
+MODULES = page_frag_test.ko
+
+obj-m += page_frag_test.o
+
+all:
+ +$(Q)make -C $(KDIR) M=$(PAGE_FRAG_TEST_DIR) modules
+
+clean:
+ +$(Q)make -C $(KDIR) M=$(PAGE_FRAG_TEST_DIR) clean
diff --git a/tools/testing/selftests/mm/page_frag/page_frag_test.c b/tools/testing/selftests/mm/page_frag/page_frag_test.c
new file mode 100644
index 000000000000..0e803db1ad79
--- /dev/null
+++ b/tools/testing/selftests/mm/page_frag/page_frag_test.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Test module for page_frag cache
+ *
+ * Copyright: linyunsheng@xxxxxxxxxx
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/cpumask.h>
+#include <linux/completion.h>
+#include <linux/ptr_ring.h>
+#include <linux/kthread.h>
+
+static struct ptr_ring ptr_ring;
+static int nr_objs = 512;
+static atomic_t nthreads;
+static struct completion wait;
+static struct page_frag_cache test_frag;
+
+static int nr_test = 5120000;
+module_param(nr_test, int, 0);
+MODULE_PARM_DESC(nr_test, "number of iterations to test");
+
+static bool test_align;
+module_param(test_align, bool, 0);
+MODULE_PARM_DESC(test_align, "use align API for testing");
+
+static int test_alloc_len = 2048;
+module_param(test_alloc_len, int, 0);
+MODULE_PARM_DESC(test_alloc_len, "alloc len for testing");
+
+static int test_push_cpu;
+module_param(test_push_cpu, int, 0);
+MODULE_PARM_DESC(test_push_cpu, "test cpu for pushing fragment");
+
+static int test_pop_cpu;
+module_param(test_pop_cpu, int, 0);
+MODULE_PARM_DESC(test_pop_cpu, "test cpu for popping fragment");
+
+static int page_frag_pop_thread(void *arg)
+{
+ struct ptr_ring *ring = arg;
+ int nr = nr_test;
+
+ pr_info("page_frag pop test thread begins on cpu %d\n",
+ smp_processor_id());
+
+ while (nr > 0) {
+ void *obj = __ptr_ring_consume(ring);
+
+ if (obj) {
+ nr--;
+ page_frag_free(obj);
+ } else {
+ cond_resched();
+ }
+ }
+
+ if (atomic_dec_and_test(&nthreads))
+ complete(&wait);
+
+ pr_info("page_frag pop test thread exits on cpu %d\n",
+ smp_processor_id());
+
+ return 0;
+}
+
+static int page_frag_push_thread(void *arg)
+{
+ struct ptr_ring *ring = arg;
+ int nr = nr_test;
+
+ pr_info("page_frag push test thread begins on cpu %d\n",
+ smp_processor_id());
+
+ while (nr > 0) {
+ void *va;
+ int ret;
+
+ if (test_align) {
+ va = page_frag_alloc_align(&test_frag, test_alloc_len,
+ GFP_KERNEL, SMP_CACHE_BYTES);
+
+ WARN_ONCE((unsigned long)va & (SMP_CACHE_BYTES - 1),
+ "unaligned va returned\n");
+ } else {
+ va = page_frag_alloc(&test_frag, test_alloc_len, GFP_KERNEL);
+ }
+
+ if (!va)
+ continue;
+
+ ret = __ptr_ring_produce(ring, va);
+ if (ret) {
+ page_frag_free(va);
+ cond_resched();
+ } else {
+ nr--;
+ }
+ }
+
+ pr_info("page_frag push test thread exits on cpu %d\n",
+ smp_processor_id());
+
+ if (atomic_dec_and_test(&nthreads))
+ complete(&wait);
+
+ return 0;
+}
+
+static int __init page_frag_test_init(void)
+{
+ struct task_struct *tsk_push, *tsk_pop;
+ ktime_t start;
+ u64 duration;
+ int ret;
+
+ test_frag.va = NULL;
+ atomic_set(&nthreads, 2);
+ init_completion(&wait);
+
+ if (test_alloc_len > PAGE_SIZE || test_alloc_len <= 0 ||
+ !cpu_active(test_push_cpu) || !cpu_active(test_pop_cpu))
+ return -EINVAL;
+
+ ret = ptr_ring_init(&ptr_ring, nr_objs, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ tsk_push = kthread_create_on_cpu(page_frag_push_thread, &ptr_ring,
+ test_push_cpu, "page_frag_push");
+ if (IS_ERR(tsk_push))
+ return PTR_ERR(tsk_push);
+
+ tsk_pop = kthread_create_on_cpu(page_frag_pop_thread, &ptr_ring,
+ test_pop_cpu, "page_frag_pop");
+ if (IS_ERR(tsk_pop)) {
+ kthread_stop(tsk_push);
+ return PTR_ERR(tsk_pop);
+ }
+
+ start = ktime_get();
+ wake_up_process(tsk_push);
+ wake_up_process(tsk_pop);
+
+ pr_info("waiting for test to complete\n");
+ wait_for_completion(&wait);
+
+ duration = (u64)ktime_us_delta(ktime_get(), start);
+ pr_info("%d of iterations for %s testing took: %lluus\n", nr_test,
+ test_align ? "aligned" : "non-aligned", duration);
+
+ ptr_ring_cleanup(&ptr_ring, NULL);
+ page_frag_cache_drain(&test_frag);
+
+ return -EAGAIN;
+}
+
+static void __exit page_frag_test_exit(void)
+{
+}
+
+module_init(page_frag_test_init);
+module_exit(page_frag_test_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yunsheng Lin <linyunsheng@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Test module for page_frag");
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 36045edb10de..9a788d5f3f28 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -75,6 +75,8 @@ separated by spaces:
read-only VMAs
- mdwe
test prctl(PR_SET_MDWE, ...)
+- page_frag
+ test handling of page fragment allocation and freeing
example: ./run_vmtests.sh -t "hmm mmap ksm"
EOF
@@ -231,7 +233,8 @@ run_test() {
("$@" 2>&1) | tap_prefix
local ret=${PIPESTATUS[0]}
count_total=$(( count_total + 1 ))
- if [ $ret -eq 0 ]; then
+ # page_frag_test.ko returns 11(EAGAIN) when insmod'ing to avoid rmmod
+ if [ $ret -eq 0 ] | [ $ret -eq 11 -a ${CATEGORY} == "page_frag" ]; then
count_pass=$(( count_pass + 1 ))
echo "[PASS]" | tap_prefix
echo "ok ${count_total} ${test}" | tap_output
@@ -456,6 +459,10 @@ CATEGORY="mkdirty" run_test ./mkdirty
CATEGORY="mdwe" run_test ./mdwe_test
+CATEGORY="page_frag" run_test insmod ./page_frag/page_frag_test.ko
+
+CATEGORY="page_frag" run_test insmod ./page_frag/page_frag_test.ko test_alloc_len=12 test_align=1
+
echo "SUMMARY: PASS=${count_pass} SKIP=${count_skip} FAIL=${count_fail}" | tap_prefix
echo "1..${count_total}" | tap_output
--
2.33.0
