From: Satheesh Rajendran <[email protected]>
Certain systems would have sparse/discontinguous
numa nodes.
perf bench numa doesnt work well on such nodes.
1. It shows wrong values.
2. It can hang.
3. It can show redundant information for non-existant nodes.
#numactl -H
available: 2 nodes (0,8)
node 0 cpus: 0 1 2 3 4 5 6 7
node 0 size: 61352 MB
node 0 free: 57168 MB
node 8 cpus: 8 9 10 11 12 13 14 15
node 8 size: 65416 MB
node 8 free: 36593 MB
node distances:
node 0 8
0: 10 40
8: 40 10
Scenario 1:
Before Fix:
# perf bench numa mem --no-data_rand_walk -p 2 -t 20 -G 0 -P 3072 -T 0 -l 50 -c -s 1000
...
...
# 40 tasks will execute (on 9 nodes, 16 CPUs): ----> Wrong number of nodes
...
# 2.0% [0.2 mins] 1/1 0/0 0/0 0/0 0/0 0/0 0/0 0/0 4/1 [ 4/2 ] l: 0-0 ( 0) ----> Shows info on non-existant nodes.
After Fix:
# ./perf bench numa mem --no-data_rand_walk -p 2 -t 20 -G 0 -P 3072 -T 0 -l 50 -c -s 1000
...
...
# 40 tasks will execute (on 2 nodes, 16 CPUs):
...
# 2.0% [0.2 mins] 9/1 0/0 [ 9/1 ] l: 0-0 ( 0)
# 4.0% [0.4 mins] 21/2 19/1 [ 2/3 ] l: 0-1 ( 1) {1-2}
Scenario 2:
Before Fix:
# perf bench numa all
# Running numa/mem benchmark...
....
...
# Running RAM-bw-remote, "perf bench numa mem -p 1 -t 1 -P 1024 -C 0 -M 1 -s 20 -zZq --thp 1 --no-data_rand_walk"
perf: bench/numa.c:306: bind_to_memnode: Assertion `!(ret)' failed. ------------> Got hung
After Fix:
# ./perf bench numa all
# Running numa/mem benchmark...
....
...
# Running RAM-bw-remote, "perf bench numa mem -p 1 -t 1 -P 1024 -C 0 -M 1 -s 20 -zZq --thp 1 --no-data_rand_walk"
# NOTE: ignoring bind NODEs starting at NODE#1
# NOTE: 0 tasks mem-bound, 1 tasks unbound
20.017 secs slowest (max) thread-runtime
20.000 secs fastest (min) thread-runtime
20.006 secs average thread-runtime
0.043 % difference between max/avg runtime
413.794 GB data processed, per thread
413.794 GB data processed, total
0.048 nsecs/byte/thread runtime
20.672 GB/sec/thread speed
20.672 GB/sec total speed
Changes in v2:
Fixed review comments for function names and alloc failure handle
Changes in v3:
Coding Style fixes.
Changes in v4:
Address review comments from Naveen and Arnaldo.
Merge two commits into single.
Changes in v5:
Removed a unwanted change and Added Acked-by.
Satheesh Rajendran (1):
perf/bench/numa: Fixup discontiguous/sparse numa nodes
tools/perf/bench/numa.c | 56 ++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 51 insertions(+), 5 deletions(-)
--
2.7.4
From 1584751409568686856@xxx Wed Nov 22 07:45:17 +0000 2017
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From: Satheesh Rajendran <[email protected]>
Certain systems are designed to have sparse/discontiguous nodes.
On such systems, perf bench numa hangs, shows wrong number of nodes
and shows values for non-existent nodes. Handle this by only
taking nodes that are exposed by kernel to userspace.
Cc: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Naveen N. Rao <[email protected]>
Reviewed-by: Srikar Dronamraju <[email protected]>
Signed-off-by: Satheesh Rajendran <[email protected]>
Signed-off-by: Balamuruhan S <[email protected]>
---
tools/perf/bench/numa.c | 56 ++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 51 insertions(+), 5 deletions(-)
diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c
index d95fdcc..944070e 100644
--- a/tools/perf/bench/numa.c
+++ b/tools/perf/bench/numa.c
@@ -216,6 +216,47 @@ static const char * const numa_usage[] = {
NULL
};
+/*
+ * To get number of numa nodes present.
+ */
+static int nr_numa_nodes(void)
+{
+ int i, nr_nodes = 0;
+
+ for (i = 0; i < g->p.nr_nodes; i++) {
+ if (numa_bitmask_isbitset(numa_nodes_ptr, i))
+ nr_nodes++;
+ }
+
+ return nr_nodes;
+}
+
+/*
+ * To check if given numa node is present.
+ */
+static int is_node_present(int node)
+{
+ return numa_bitmask_isbitset(numa_nodes_ptr, node);
+}
+
+/*
+ * To check given numa node has cpus.
+ */
+static bool node_has_cpus(int node)
+{
+ struct bitmask *cpu = numa_allocate_cpumask();
+ unsigned int i;
+
+ if (cpu && !numa_node_to_cpus(node, cpu)) {
+ for (i = 0; i < cpu->size; i++) {
+ if (numa_bitmask_isbitset(cpu, i))
+ return true;
+ }
+ }
+
+ return false; /* lets fall back to nocpus safely */
+}
+
static cpu_set_t bind_to_cpu(int target_cpu)
{
cpu_set_t orig_mask, mask;
@@ -244,12 +285,12 @@ static cpu_set_t bind_to_cpu(int target_cpu)
static cpu_set_t bind_to_node(int target_node)
{
- int cpus_per_node = g->p.nr_cpus/g->p.nr_nodes;
+ int cpus_per_node = g->p.nr_cpus / nr_numa_nodes();
cpu_set_t orig_mask, mask;
int cpu;
int ret;
- BUG_ON(cpus_per_node*g->p.nr_nodes != g->p.nr_cpus);
+ BUG_ON(cpus_per_node * nr_numa_nodes() != g->p.nr_cpus);
BUG_ON(!cpus_per_node);
ret = sched_getaffinity(0, sizeof(orig_mask), &orig_mask);
@@ -649,7 +690,7 @@ static int parse_setup_node_list(void)
int i;
for (i = 0; i < mul; i++) {
- if (t >= g->p.nr_tasks) {
+ if (t >= g->p.nr_tasks || !node_has_cpus(bind_node)) {
printf("\n# NOTE: ignoring bind NODEs starting at NODE#%d\n", bind_node);
goto out;
}
@@ -964,6 +1005,8 @@ static void calc_convergence(double runtime_ns_max, double *convergence)
sum = 0;
for (node = 0; node < g->p.nr_nodes; node++) {
+ if (!is_node_present(node))
+ continue;
nr = nodes[node];
nr_min = min(nr, nr_min);
nr_max = max(nr, nr_max);
@@ -984,8 +1027,11 @@ static void calc_convergence(double runtime_ns_max, double *convergence)
process_groups = 0;
for (node = 0; node < g->p.nr_nodes; node++) {
- int processes = count_node_processes(node);
+ int processes;
+ if (!is_node_present(node))
+ continue;
+ processes = count_node_processes(node);
nr = nodes[node];
tprintf(" %2d/%-2d", nr, processes);
@@ -1291,7 +1337,7 @@ static void print_summary(void)
printf("\n ###\n");
printf(" # %d %s will execute (on %d nodes, %d CPUs):\n",
- g->p.nr_tasks, g->p.nr_tasks == 1 ? "task" : "tasks", g->p.nr_nodes, g->p.nr_cpus);
+ g->p.nr_tasks, g->p.nr_tasks == 1 ? "task" : "tasks", nr_numa_nodes(), g->p.nr_cpus);
printf(" # %5dx %5ldMB global shared mem operations\n",
g->p.nr_loops, g->p.bytes_global/1024/1024);
printf(" # %5dx %5ldMB process shared mem operations\n",
--
2.7.4
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