@@ -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
@@ -125,6 +127,7 @@ TEST_FILES += test_hmm.sh
TEST_FILES += va_high_addr_switch.sh
TEST_FILES += charge_reserved_hugetlb.sh
TEST_FILES += hugetlb_reparenting_test.sh
+TEST_FILES += test_page_frag.sh
# required by charge_reserved_hugetlb.sh
TEST_FILES += write_hugetlb_memory.sh
new file mode 100644
@@ -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
new file mode 100644
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Test module for page_frag cache
+ *
+ * Copyright (C) 2024 Yunsheng Lin <linyunsheng@huawei.com>
+ */
+
+#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_nc;
+
+static int nr_test = 2000000;
+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_nc, 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_nc, 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_nc.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_nc);
+
+ 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@huawei.com>");
+MODULE_DESCRIPTION("Test module for page_frag");
@@ -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
@@ -456,6 +458,12 @@ CATEGORY="mkdirty" run_test ./mkdirty
CATEGORY="mdwe" run_test ./mdwe_test
+CATEGORY="page_frag" run_test ./test_page_frag.sh smoke
+
+CATEGORY="page_frag" run_test ./test_page_frag.sh aligned
+
+CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned
+
echo "SUMMARY: PASS=${count_pass} SKIP=${count_skip} FAIL=${count_fail}" | tap_prefix
echo "1..${count_total}" | tap_output
new file mode 100755
@@ -0,0 +1,171 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2024 Yunsheng Lin <linyunsheng@huawei.com>
+# Copyright (C) 2018 Uladzislau Rezki (Sony) <urezki@gmail.com>
+#
+# This is a test script for the kernel test driver to test the
+# correctness and performance of page_frag's implementation.
+# Therefore it is just a kernel module loader. You can specify
+# and pass different parameters in order to:
+# a) analyse performance of page fragment allocations;
+# b) stressing and stability check of page_frag subsystem.
+
+DRIVER="./page_frag/page_frag_test.ko"
+CPU_LIST=$(grep -m 2 processor /proc/cpuinfo | cut -d ' ' -f 2)
+TEST_CPU_0=$(echo $CPU_LIST | awk '{print $1}')
+
+if [ $(echo $CPU_LIST | wc -w) -gt 1 ]; then
+ TEST_CPU_1=$(echo $CPU_LIST | awk '{print $2}')
+ NR_TEST=100000000
+else
+ TEST_CPU_1=$TEST_CPU_0
+ NR_TEST=1000000
+fi
+
+# 1 if fails
+exitcode=1
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+#
+# Static templates for testing of page_frag APIs.
+# Also it is possible to pass any supported parameters manually.
+#
+SMOKE_PARAM="test_push_cpu=$TEST_CPU_0 test_pop_cpu=$TEST_CPU_1"
+NONALIGNED_PARAM="$SMOKE_PARAM test_alloc_len=75 nr_test=$NR_TEST"
+ALIGNED_PARAM="$NONALIGNED_PARAM test_align=1"
+
+check_test_requirements()
+{
+ uid=$(id -u)
+ if [ $uid -ne 0 ]; then
+ echo "$0: Must be run as root"
+ exit $ksft_skip
+ fi
+
+ if ! which insmod > /dev/null 2>&1; then
+ echo "$0: You need insmod installed"
+ exit $ksft_skip
+ fi
+
+ if [ ! -f $DRIVER ]; then
+ echo "$0: You need to compile page_frag_test module"
+ exit $ksft_skip
+ fi
+}
+
+run_nonaligned_check()
+{
+ echo "Run performance tests to evaluate how fast nonaligned alloc API is."
+
+ insmod $DRIVER $NONALIGNED_PARAM > /dev/null 2>&1
+ echo "Done."
+ echo "Ccheck the kernel ring buffer to see the summary."
+}
+
+run_aligned_check()
+{
+ echo "Run performance tests to evaluate how fast aligned alloc API is."
+
+ insmod $DRIVER $ALIGNED_PARAM > /dev/null 2>&1
+ echo "Done."
+ echo "Check the kernel ring buffer to see the summary."
+}
+
+run_smoke_check()
+{
+ echo "Run smoke test."
+
+ insmod $DRIVER $SMOKE_PARAM > /dev/null 2>&1
+ echo "Done."
+ echo "Check the kernel ring buffer to see the summary."
+}
+
+usage()
+{
+ echo -n "Usage: $0 [ aligned ] | [ nonaligned ] | | [ smoke ] | "
+ echo "manual parameters"
+ echo
+ echo "Valid tests and parameters:"
+ echo
+ modinfo $DRIVER
+ echo
+ echo "Example usage:"
+ echo
+ echo "# Shows help message"
+ echo "$0"
+ echo
+ echo "# Smoke testing"
+ echo "$0 smoke"
+ echo
+ echo "# Performance testing for nonaligned alloc API"
+ echo "$0 nonaligned"
+ echo
+ echo "# Performance testing for aligned alloc API"
+ echo "$0 aligned"
+ echo
+ exit 0
+}
+
+function validate_passed_args()
+{
+ VALID_ARGS=`modinfo $DRIVER | awk '/parm:/ {print $2}' | sed 's/:.*//'`
+
+ #
+ # Something has been passed, check it.
+ #
+ for passed_arg in $@; do
+ key=${passed_arg//=*/}
+ valid=0
+
+ for valid_arg in $VALID_ARGS; do
+ if [[ $key = $valid_arg ]]; then
+ valid=1
+ break
+ fi
+ done
+
+ if [[ $valid -ne 1 ]]; then
+ echo "Error: key is not correct: ${key}"
+ exit $exitcode
+ fi
+ done
+}
+
+function run_manual_check()
+{
+ #
+ # Validate passed parameters. If there is wrong one,
+ # the script exists and does not execute further.
+ #
+ validate_passed_args $@
+
+ echo "Run the test with following parameters: $@"
+ insmod $DRIVER $@ > /dev/null 2>&1
+ echo "Done."
+ echo "Check the kernel ring buffer to see the summary."
+}
+
+function run_test()
+{
+ if [ $# -eq 0 ]; then
+ usage
+ else
+ if [[ "$1" = "smoke" ]]; then
+ run_smoke_check
+ elif [[ "$1" = "nonaligned" ]]; then
+ run_nonaligned_check
+ elif [[ "$1" = "aligned" ]]; then
+ run_aligned_check
+ else
+ run_manual_check $@
+ fi
+ fi
+}
+
+check_test_requirements
+run_test $@
+
+exit 0
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@gmail.com> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> --- tools/testing/selftests/mm/Makefile | 3 + tools/testing/selftests/mm/page_frag/Makefile | 18 ++ .../selftests/mm/page_frag/page_frag_test.c | 170 +++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 8 + tools/testing/selftests/mm/test_page_frag.sh | 171 ++++++++++++++++++ 5 files changed, 370 insertions(+) create mode 100644 tools/testing/selftests/mm/page_frag/Makefile create mode 100644 tools/testing/selftests/mm/page_frag/page_frag_test.c create mode 100755 tools/testing/selftests/mm/test_page_frag.sh