lib: Add memperf test

This patch adds a custom test for measuring performance of
memcpy(), memset(), and memmove() functions

DO NOT UPSTREAM !!!!!

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

lib/Kconfig

@@ -8,6 +8,13 @@ config BINARY_PRINTF
 
 menu "Library routines"
 
+config MEMPERF_TEST
+	tristate "Mem* performance tests"
+	depends on CONTIG_ALLOC
+	default n
+	help
+	  Check performance of memcpy, memset, and memmove functions.
+
 config RAID6_PQ
 	tristate
 

lib/Makefile

@@ -366,6 +366,8 @@ obj-$(CONFIG_MEMCPY_KUNIT_TEST) += memcpy_kunit.o
 
 obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
 
+obj-$(CONFIG_MEMPERF_TEST) += memperf_test.o
+
 # FORTIFY_SOURCE compile-time behavior tests
 TEST_FORTIFY_SRCS = $(wildcard $(srctree)/$(src)/test_fortify/*-*.c)
 TEST_FORTIFY_LOGS = $(patsubst $(srctree)/$(src)/%.c, %.log, $(TEST_FORTIFY_SRCS))

lib/memperf_test.c

@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timekeeping.h>
+
+static unsigned long memorder  = 12;
+module_param(memorder, ulong, 0600);
+MODULE_PARM_DESC(memorder, "Log2 of number of pages");
+
+static unsigned long linesz = sizeof(long);
+module_param(linesz, ulong, 0600);
+MODULE_PARM_DESC(linesz, "Size of cache line");
+
+#define MEM_ORDER	memorder
+#define MEM_PAGES	BIT(MEM_ORDER)
+#define MEM_SIZE	(PAGE_SIZE * MEM_PAGES)
+
+static __init void memset_perf_test(void)
+{
+	int i;
+	void *dst;
+	ktime_t t0, t1;
+	struct page *dpage;
+	unsigned long long mbps;
+
+	printk("memperf: memset test linesz=%lu memorder=%lu memsize=%luMB\n\n",
+		linesz, MEM_ORDER, MEM_SIZE / 1048576UL);
+
+	dpage = alloc_contig_pages(MEM_PAGES, GFP_KERNEL, NUMA_NO_NODE, 0);
+	dst = page_to_virt(dpage);
+
+	for (i = 0; i < linesz; i++) {
+		t0 = ktime_get();
+		memset(dst + i, 0 + i, MEM_SIZE - i);
+		t1 = ktime_get();
+		mbps = MEM_SIZE * (1000000000ULL / 1048576ULL) * 8ULL;
+		mbps = mbps / (t1 - t0);
+		printk("memperf: memset(dst+%d): %llu Mb/s\n", i, mbps);
+	}
+
+	free_contig_range(page_to_pfn(dpage), MEM_PAGES);
+
+	printk("\n");
+}
+
+static __init void memcpy_memmove_perf_test(bool cpy)
+{
+	int i, j;
+	ktime_t t0, t1;
+	void *src, *dst;
+	unsigned long long mbps;
+	struct page *spage, *dpage;
+
+	printk("memperf: %s test linesz=%lu memorder=%lu memsize=%luMB,\n\n",
+		(cpy) ? "memcpy" : "memmove", linesz,
+		MEM_ORDER, MEM_SIZE / 1048576UL);
+
+	spage = alloc_contig_pages(MEM_PAGES, GFP_KERNEL, NUMA_NO_NODE, 0);
+	src = page_to_virt(spage);
+	dpage = alloc_contig_pages(MEM_PAGES, GFP_KERNEL, NUMA_NO_NODE, 0);
+	dst = page_to_virt(dpage);
+
+	for (i = 0; i < linesz; i++) {
+		for (j = 0; j < linesz; j++) {
+			t0 = ktime_get();
+			if (cpy)
+				memcpy(dst + i, src + j, MEM_SIZE - max(i, j));
+			else
+				memmove(dst + i, src + j, MEM_SIZE - max(i, j));
+			t1 = ktime_get();
+			mbps = MEM_SIZE * (1000000000ULL / 1048576ULL) * 8ULL;
+			mbps = mbps / (t1 - t0);
+			printk("memperf: %s(dst+%d, src+%d), distance %lu: %llu Mb/s\n",
+				(cpy) ? "memcpy" : "memmove", i, j,
+				(j - i) % sizeof(long), mbps);
+		}
+		printk("\n");
+	}
+
+	free_contig_range(page_to_pfn(dpage), MEM_PAGES);
+	free_contig_range(page_to_pfn(spage), MEM_PAGES);
+}
+
+static __init int memperf_test_init(void)
+{
+	/* Do memset() performance test */
+	memset_perf_test();
+
+	/* Do memcpy() performance test */
+	memcpy_memmove_perf_test(true);
+
+	/* Do memmove() performance test */
+	memcpy_memmove_perf_test(false);
+
+	return 0;
+}
+
+static __exit void memperf_test_exit(void)
+{
+}
+
+module_init(memperf_test_init);
+module_exit(memperf_test_exit);
+MODULE_LICENSE("GPL v2");