diff options
Diffstat (limited to 'kernel/dma/map_benchmark.c')
| -rw-r--r-- | kernel/dma/map_benchmark.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c index 02205ab53b7e..cc19a3efea89 100644 --- a/kernel/dma/map_benchmark.c +++ b/kernel/dma/map_benchmark.c @@ -89,6 +89,22 @@ static int map_benchmark_thread(void *data) atomic64_add(map_sq, &map->sum_sq_map); atomic64_add(unmap_sq, &map->sum_sq_unmap); atomic64_inc(&map->loops); + + /* + * We may test for a long time so periodically check whether + * we need to schedule to avoid starving the others. Otherwise + * we may hangup the kernel in a non-preemptible kernel when + * the test kthreads number >= CPU number, the test kthreads + * will run endless on every CPU since the thread resposible + * for notifying the kthread stop (in do_map_benchmark()) + * could not be scheduled. + * + * Note this may degrade the test concurrency since the test + * threads may need to share the CPU time with other load + * in the system. So it's recommended to run this benchmark + * on an idle system. + */ + cond_resched(); } out: @@ -101,7 +117,6 @@ static int do_map_benchmark(struct map_benchmark_data *map) struct task_struct **tsk; int threads = map->bparam.threads; int node = map->bparam.node; - const cpumask_t *cpu_mask = cpumask_of_node(node); u64 loops; int ret = 0; int i; @@ -118,11 +133,13 @@ static int do_map_benchmark(struct map_benchmark_data *map) if (IS_ERR(tsk[i])) { pr_err("create dma_map thread failed\n"); ret = PTR_ERR(tsk[i]); + while (--i >= 0) + kthread_stop(tsk[i]); goto out; } if (node != NUMA_NO_NODE) - kthread_bind_mask(tsk[i], cpu_mask); + kthread_bind_mask(tsk[i], cpumask_of_node(node)); } /* clear the old value in the previous benchmark */ @@ -139,13 +156,17 @@ static int do_map_benchmark(struct map_benchmark_data *map) msleep_interruptible(map->bparam.seconds * 1000); - /* wait for the completion of benchmark threads */ + /* wait for the completion of all started benchmark threads */ for (i = 0; i < threads; i++) { - ret = kthread_stop(tsk[i]); - if (ret) - goto out; + int kthread_ret = kthread_stop_put(tsk[i]); + + if (kthread_ret) + ret = kthread_ret; } + if (ret) + goto out; + loops = atomic64_read(&map->loops); if (likely(loops > 0)) { u64 map_variance, unmap_variance; @@ -170,8 +191,6 @@ static int do_map_benchmark(struct map_benchmark_data *map) } out: - for (i = 0; i < threads; i++) - put_task_struct(tsk[i]); put_device(map->dev); kfree(tsk); return ret; @@ -208,7 +227,8 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd, } if (map->bparam.node != NUMA_NO_NODE && - !node_possible(map->bparam.node)) { + (map->bparam.node < 0 || map->bparam.node >= MAX_NUMNODES || + !node_possible(map->bparam.node))) { pr_err("invalid numa node\n"); return -EINVAL; } @@ -252,6 +272,9 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd, * dma_mask changed by benchmark */ dma_set_mask(map->dev, old_dma_mask); + + if (ret) + return ret; break; default: return -EINVAL; |