[patch 177/262] selftest/vm: fix ksm selftest to run with different NUMA topologies

Andrew Morton
2021-11-05T20:52:09Z

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: selftest/vm: fix ksm selftest to run with different NUMA topologies

Platforms can have non-contiguous NUMA nodes like below

#numactl -H
available: 2 nodes (0,8)
.....
node distances:
node 0 8
0: 10 40
8: 40 10

#numactl -H
available: 1 nodes (1)
....
node distances:
node 1
1: 10

Hence update the test to not assume the presence of Node 0 and 1 and also
use numa_num_configured_nodes() instead of numa_max_node for finding
whether to skip the test.

Link: https://lkml.kernel.org/r/20210914141414.350759-1-aneesh.kumar@linux.ibm.com
Fixes: 82e717ad3501 ("selftests: vm: add KSM merging across nodes test")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

tools/testing/selftests/vm/ksm_tests.c | 29 ++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)

--- a/tools/testing/selftests/vm/ksm_tests.c~selftest-vm-fix-ksm-selftest-to-run-with-different-numa-topologies
+++ a/tools/testing/selftests/vm/ksm_tests.c
@@ -354,12 +354,34 @@ err_out:
return KSFT_FAIL;
}

+static int get_next_mem_node(int node)
+{
+
+ long node_size;
+ int mem_node = 0;
+ int i, max_node = numa_max_node();
+
+ for (i = node + 1; i <= max_node + node; i++) {
+ mem_node = i % (max_node + 1);
+ node_size = numa_node_size(mem_node, NULL);
+ if (node_size > 0)
+ break;
+ }
+ return mem_node;
+}
+
+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)
{
void *numa1_map_ptr, *numa2_map_ptr;
struct timespec start_time;
int page_count = 2;
+ int first_node;

if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
perror("clock_gettime");
@@ -370,7 +392,7 @@ static int check_ksm_numa_merge(int mapp
perror("NUMA support not enabled");
return KSFT_SKIP;
}
- if (numa_max_node() < 1) {
+ if (numa_num_configured_nodes() <= 1) {
printf("At least 2 NUMA nodes must be available\n");
return KSFT_SKIP;
}
@@ -378,8 +400,9 @@ static int check_ksm_numa_merge(int mapp
return KSFT_FAIL;

/* allocate 2 pages in 2 different NUMA nodes and fill them with the same data */
- numa1_map_ptr = numa_alloc_onnode(page_size, 0);
- numa2_map_ptr = numa_alloc_onnode(page_size, 1);
+ first_node = get_first_mem_node();
+ numa1_map_ptr = numa_alloc_onnode(page_size, first_node);
+ numa2_map_ptr = numa_alloc_onnode(page_size, get_next_mem_node(first_node));
if (!numa1_map_ptr || !numa2_map_ptr) {
perror("numa_alloc_onnode");
return KSFT_FAIL;
_