[RESEND RFC PATCH v1 17/20] selftests/vm: add KSM prctl merge test

23 Jan 2023

This adds the -t option to the ksm_tests program. The -t flag allows to
specify if it should use madvise or prctl ksm merging.
Signed-off-by: Stefan Roesch shr@devkernel.io
---
 tools/testing/selftests/vm/Makefile    |   3 +-
 tools/testing/selftests/vm/ksm_tests.c | 116 +++++++++++++++++--------
 2 files changed, 80 insertions(+), 39 deletions(-)

diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 89c14e41bd43..8a50802d8700 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -25,7 +25,8 @@ MACHINE ?= $(shell echo $(uname_M) | sed -e 's/aarch64.*/arm64/' -e 's/ppc64.*/p
 # LDLIBS.
 MAKEFLAGS += --no-builtin-rules
-CFLAGS = -Wall -I $(top_srcdir) -I $(top_srcdir)/usr/include $(EXTRA_CFLAGS) $(KHDR_INCLUDES)
+CFLAGS = -Wall -I $(top_srcdir)/tools/include/uapi
+CFLAGS += -I $(top_srcdir) -I $(top_srcdir)/usr/include $(EXTRA_CFLAGS) $(KHDR_INCLUDES)
 LDLIBS = -lrt -lpthread
 TEST_GEN_FILES = cow
 TEST_GEN_FILES += compaction_test
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c
index f9eb4d67e0dd..386a0929c8a3 100644
--- a/tools/testing/selftests/vm/ksm_tests.c
+++ b/tools/testing/selftests/vm/ksm_tests.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
 #include <stdbool.h>
 #include <time.h>
 #include <string.h>
@@ -21,6 +23,7 @@
 #define KSM_PROT_STR_DEFAULT "rw"
 #define KSM_USE_ZERO_PAGES_DEFAULT false
 #define KSM_MERGE_ACROSS_NODES_DEFAULT true
+#define KSM_MERGE_TYPE_DEFAULT 0
 #define MB (1ul << 20)
struct ksm_sysfs {
@@ -33,6 +36,12 @@ struct ksm_sysfs {
    unsigned long use_zero_pages;
 };
+enum ksm_merge_type {
+	KSM_MERGE_MADVISE,
+	KSM_MERGE_PRCTL,
+	KSM_MERGE_LAST = KSM_MERGE_PRCTL
+};
+
 enum ksm_test_name {
    CHECK_KSM_MERGE,
    CHECK_KSM_UNMERGE,
@@ -129,6 +138,10 @@ static void print_help(void)
    printf(" -m: change merge_across_nodes tunable\n"
           "     Default: %d\n", KSM_MERGE_ACROSS_NODES_DEFAULT);
    printf(" -s: the size of duplicated memory area (in MiB)\n");
+	printf(" -t: KSM merge type\n"
+	       "     Default: 0\n"
+	       "     0: madvise merging\n"
+	       "     1: prctl merging\n");
exit(0);
 }
@@ -176,12 +189,21 @@ static int ksm_do_scan(int scan_count, struct timespec start_time, int timeout)
    return 0;
 }
-static int ksm_merge_pages(void *addr, size_t size, struct timespec start_time, int timeout)
+static int ksm_merge_pages(int merge_type, void *addr, size_t size,
+			struct timespec start_time, int timeout)
 {
-	if (madvise(addr, size, MADV_MERGEABLE)) {
-		perror("madvise");
-		return 1;
+	if (merge_type == KSM_MERGE_MADVISE) {
+		if (madvise(addr, size, MADV_MERGEABLE)) {
+			perror("madvise");
+			return 1;
+		}
+	} else if (merge_type == KSM_MERGE_PRCTL) {
+		if (prctl(PR_SET_MEMORY_MERGE, 1)) {
+			perror("prctl");
+			return 1;
+		}
    }
+
    if (ksm_write_sysfs(KSM_FP("run"), 1))
    	return 1;
@@ -266,7 +288,8 @@ static int ksm_restore(struct ksm_sysfs *ksm_sysfs)
    return 0;
 }
-static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, size_t page_size)
+static int check_ksm_merge(int merge_type, int mapping, int prot,
+			long page_count, int timeout, size_t page_size)
 {
    void *map_ptr;
    struct timespec start_time;
@@ -281,13 +304,16 @@ static int check_ksm_merge(int mapping, int prot, long page_count, int timeout,
    if (!map_ptr)
    	return KSFT_FAIL;
-	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
    	goto err_out;
/* verify that the right number of pages are merged */
    if (assert_ksm_pages_count(page_count)) {
    	printf("OK\n");
-		munmap(map_ptr, page_size * page_count);
+		if (merge_type == KSM_MERGE_MADVISE)
+			munmap(map_ptr, page_size * page_count);
+		else if (merge_type == KSM_MERGE_PRCTL)
+			prctl(PR_SET_MEMORY_MERGE, 0);
    	return KSFT_PASS;
    }
@@ -297,7 +323,7 @@ static int check_ksm_merge(int mapping, int prot, long page_count, int timeout,
    return KSFT_FAIL;
 }
-static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_size)
+static int check_ksm_unmerge(int merge_type, int mapping, int prot, int timeout, size_t page_size)
 {
    void *map_ptr;
    struct timespec start_time;
@@ -313,7 +339,7 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz
    if (!map_ptr)
    	return KSFT_FAIL;
-	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
    	goto err_out;
/* change 1 byte in each of the 2 pages -- KSM must automatically unmerge them */
@@ -337,8 +363,8 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz
    return KSFT_FAIL;
 }
-static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout,
-				     bool use_zero_pages, size_t page_size)
+static int check_ksm_zero_page_merge(int merge_type, int mapping, int prot, long page_count,
+				int timeout, bool use_zero_pages, size_t page_size)
 {
    void *map_ptr;
    struct timespec start_time;
@@ -356,7 +382,7 @@ static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int
    if (!map_ptr)
    	return KSFT_FAIL;
-	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
    	goto err_out;
/*
@@ -402,8 +428,8 @@ static int get_first_mem_node(void)
    return get_next_mem_node(numa_max_node());
 }
-static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_across_nodes,
-				size_t page_size)
+static int check_ksm_numa_merge(int merge_type, int mapping, int prot, int timeout,
+				bool merge_across_nodes, size_t page_size)
 {
    void *numa1_map_ptr, *numa2_map_ptr;
    struct timespec start_time;
@@ -439,8 +465,8 @@ static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_a
    memset(numa2_map_ptr, '*', page_size);
/* try to merge the pages */
-	if (ksm_merge_pages(numa1_map_ptr, page_size, start_time, timeout) ||
-	    ksm_merge_pages(numa2_map_ptr, page_size, start_time, timeout))
+	if (ksm_merge_pages(merge_type, numa1_map_ptr, page_size, start_time, timeout) ||
+	    ksm_merge_pages(merge_type, numa2_map_ptr, page_size, start_time, timeout))
    	goto err_out;
/*
@@ -466,7 +492,8 @@ static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_a
    return KSFT_FAIL;
 }
-static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t map_size)
+static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
+				int timeout, size_t map_size)
 {
    void *map_ptr, *map_ptr_orig;
    struct timespec start_time, end_time;
@@ -508,7 +535,7 @@ static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t m
    	perror("clock_gettime");
    	goto err_out;
    }
-	if (ksm_merge_pages(map_ptr, map_size, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout))
    	goto err_out;
    if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
    	perror("clock_gettime");
@@ -533,7 +560,7 @@ static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t m
    return KSFT_FAIL;
 }
-static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size)
+static int ksm_merge_time(int merge_type, int mapping, int prot, int timeout, size_t map_size)
 {
    void *map_ptr;
    struct timespec start_time, end_time;
@@ -549,7 +576,7 @@ static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size)
    	perror("clock_gettime");
    	goto err_out;
    }
-	if (ksm_merge_pages(map_ptr, map_size, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout))
    	goto err_out;
    if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
    	perror("clock_gettime");
@@ -574,7 +601,7 @@ static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size)
    return KSFT_FAIL;
 }
-static int ksm_unmerge_time(int mapping, int prot, int timeout, size_t map_size)
+static int ksm_unmerge_time(int merge_type, int mapping, int prot, int timeout, size_t map_size)
 {
    void *map_ptr;
    struct timespec start_time, end_time;
@@ -589,7 +616,7 @@ static int ksm_unmerge_time(int mapping, int prot, int timeout, size_t map_size)
    	perror("clock_gettime");
    	goto err_out;
    }
-	if (ksm_merge_pages(map_ptr, map_size, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout))
    	goto err_out;
if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
@@ -621,7 +648,7 @@ static int ksm_unmerge_time(int mapping, int prot, int timeout, size_t map_size)
    return KSFT_FAIL;
 }
-static int ksm_cow_time(int mapping, int prot, int timeout, size_t page_size)
+static int ksm_cow_time(int merge_type, int mapping, int prot, int timeout, size_t page_size)
 {
    void *map_ptr;
    struct timespec start_time, end_time;
@@ -660,7 +687,7 @@ static int ksm_cow_time(int mapping, int prot, int timeout, size_t page_size)
    	memset(map_ptr + page_size * i, '+', i / 2 + 1);
    	memset(map_ptr + page_size * (i + 1), '+', i / 2 + 1);
    }
-	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+	if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
    	goto err_out;
if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
@@ -697,6 +724,7 @@ int main(int argc, char *argv[])
    int ret, opt;
    int prot = 0;
    int ksm_scan_limit_sec = KSM_SCAN_LIMIT_SEC_DEFAULT;
+	int merge_type = KSM_MERGE_TYPE_DEFAULT;
    long page_count = KSM_PAGE_COUNT_DEFAULT;
    size_t page_size = sysconf(_SC_PAGESIZE);
    struct ksm_sysfs ksm_sysfs_old;
@@ -705,7 +733,7 @@ int main(int argc, char *argv[])
    bool merge_across_nodes = KSM_MERGE_ACROSS_NODES_DEFAULT;
    long size_MB = 0;
-	while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:MUZNPCHD")) != -1) {
+	while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:t:MUZNPCHD")) != -1) {
    	switch (opt) {
    	case 'a':
    		prot = str_to_prot(optarg);
@@ -745,6 +773,17 @@ int main(int argc, char *argv[])
    			printf("Size must be greater than 0\n");
    			return KSFT_FAIL;
    		}
+		case 't':
+			{
+				int tmp = atoi(optarg);
+
+				if (tmp < 0 || tmp > KSM_MERGE_LAST) {
+					printf("Invalid merge type\n");
+					return KSFT_FAIL;
+				}
+				merge_type = atoi(optarg);
+			}
+			break;
    	case 'M':
    		break;
    	case 'U':
@@ -795,35 +834,36 @@ int main(int argc, char *argv[])
switch (test_name) {
    case CHECK_KSM_MERGE:
-		ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
+		ret = check_ksm_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
    			      ksm_scan_limit_sec, page_size);
    	break;
    case CHECK_KSM_UNMERGE:
-		ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
-					page_size);
+		ret = check_ksm_unmerge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
+					ksm_scan_limit_sec, page_size);
    	break;
    case CHECK_KSM_ZERO_PAGE_MERGE:
-		ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
-						ksm_scan_limit_sec, use_zero_pages, page_size);
+		ret = check_ksm_zero_page_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
+						page_count, ksm_scan_limit_sec, use_zero_pages,
+						page_size);
    	break;
    case CHECK_KSM_NUMA_MERGE:
-		ret = check_ksm_numa_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
-					   merge_across_nodes, page_size);
+		ret = check_ksm_numa_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
+					ksm_scan_limit_sec, merge_across_nodes, page_size);
    	break;
    case KSM_MERGE_TIME:
    	if (size_MB == 0) {
    		printf("Option '-s' is required.\n");
    		return KSFT_FAIL;
    	}
-		ret = ksm_merge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
-				     size_MB);
+		ret = ksm_merge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
+				ksm_scan_limit_sec, size_MB);
    	break;
    case KSM_MERGE_TIME_HUGE_PAGES:
    	if (size_MB == 0) {
    		printf("Option '-s' is required.\n");
    		return KSFT_FAIL;
    	}
-		ret = ksm_merge_hugepages_time(MAP_PRIVATE | MAP_ANONYMOUS, prot,
+		ret = ksm_merge_hugepages_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
    			ksm_scan_limit_sec, size_MB);
    	break;
    case KSM_UNMERGE_TIME:
@@ -831,12 +871,12 @@ int main(int argc, char *argv[])
    		printf("Option '-s' is required.\n");
    		return KSFT_FAIL;
    	}
-		ret = ksm_unmerge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot,
+		ret = ksm_unmerge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
    			       ksm_scan_limit_sec, size_MB);
    	break;
    case KSM_COW_TIME:
-		ret = ksm_cow_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
-				   page_size);
+		ret = ksm_cow_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
+				ksm_scan_limit_sec, page_size);
    	break;
    }
-- 
2.30.2


    

2024

2023

2022

2021

2020

2019

2018

2017

[RESEND RFC PATCH v1 17/20] selftests/vm: add KSM prctl merge test