From: Alexander Gordeev <agordeev@linux.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Ingo Molnar <mingo@redhat.com>
Subject: [PATCH v2 1/3] perf bench numa: fix incorrect NUMA toplogy assumption
Date: Tue, 30 Jun 2020 18:18:42 +0200 [thread overview]
Message-ID: <20200630161842.GA29743@oc3871087118.ibm.com> (raw)
In-Reply-To: <a53eedd6ad2fb46aec4d59066277aad7ace470b7.1593445668.git.agordeev@linux.ibm.com>
The current code assumes that CPUs are evenly spread among
NUMA nodes. That is generally incorrect and leads to failure
on systems that have different NUMA topology.
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
---
tools/perf/bench/numa.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c
index 5797253..23e224e 100644
--- a/tools/perf/bench/numa.c
+++ b/tools/perf/bench/numa.c
@@ -247,12 +247,13 @@ static int is_node_present(int node)
*/
static bool node_has_cpus(int node)
{
- struct bitmask *cpu = numa_allocate_cpumask();
+ struct bitmask *cpumask = 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))
+ BUG_ON(!cpumask);
+ if (!numa_node_to_cpus(node, cpumask)) {
+ for (i = 0; i < cpumask->size; i++) {
+ if (numa_bitmask_isbitset(cpumask, i))
return true;
}
}
@@ -288,14 +289,10 @@ 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 / nr_numa_nodes();
cpu_set_t orig_mask, mask;
int cpu;
int ret;
- 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);
BUG_ON(ret);
@@ -305,13 +302,15 @@ static cpu_set_t bind_to_node(int target_node)
for (cpu = 0; cpu < g->p.nr_cpus; cpu++)
CPU_SET(cpu, &mask);
} else {
- int cpu_start = (target_node + 0) * cpus_per_node;
- int cpu_stop = (target_node + 1) * cpus_per_node;
-
- BUG_ON(cpu_stop > g->p.nr_cpus);
+ struct bitmask *cpumask = numa_allocate_cpumask();
- for (cpu = cpu_start; cpu < cpu_stop; cpu++)
- CPU_SET(cpu, &mask);
+ BUG_ON(!cpumask);
+ if (!numa_node_to_cpus(target_node, cpumask)) {
+ for (cpu = 0; cpu < (int)cpumask->size; cpu++) {
+ if (numa_bitmask_isbitset(cpumask, cpu))
+ CPU_SET(cpu, &mask);
+ }
+ }
}
ret = sched_setaffinity(0, sizeof(mask), &mask);
--
1.8.3.1
next prev parent reply other threads:[~2020-06-30 16:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-29 15:50 [PATCH 0/3] perf bench numa: fix few minor issues Alexander Gordeev
2020-06-29 15:50 ` [PATCH 1/3] perf bench numa: fix incorrect NUMA toplogy assumption Alexander Gordeev
2020-06-30 16:18 ` Alexander Gordeev
2020-06-30 16:18 ` Alexander Gordeev [this message]
2020-06-29 15:50 ` [PATCH 2/3] perf bench numa: fix benchmark names Alexander Gordeev
2020-06-29 15:50 ` [PATCH 3/3] perf bench numa: fix wrong benchmark configuration Alexander Gordeev
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