diff options
Diffstat (limited to 'kernel/dma/map_benchmark.c')
| -rw-r--r-- | kernel/dma/map_benchmark.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c index 4950e0b622b1..794041a39e65 100644 --- a/kernel/dma/map_benchmark.c +++ b/kernel/dma/map_benchmark.c @@ -11,13 +11,13 @@ #include <linux/dma-mapping.h> #include <linux/kernel.h> #include <linux/kthread.h> -#include <linux/map_benchmark.h> #include <linux/math64.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/timekeeping.h> +#include <uapi/linux/map_benchmark.h> struct map_benchmark_data { struct map_benchmark bparam; @@ -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: |