From: Steven Rostedt Running the ring-buffer-benchmark's threads at the lowest priority may work well for keeping it in the background, but it is not appropriate for the benchmarks. This patch adds 4 parameters to the module: consumer_fifo consumer_nice producer_fifo producer_nice By default the consumer and producer still run at nice +19. If the *_fifo options are set, they will override the *_nice values. modprobe ring_buffer_benchmark consumer_nice=0 producer_fifo=10 The above will set the consumer thread to a nice value of 0, and the producer thread to a RT SCHED_FIFO priority of 10. Note, this patch also fixes a bug where calling set_user_nice on the consumer thread would oops the kernel when the parameter "disable_reader" is set. Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer_benchmark.c | 58 ++++++++++++++++++++++++++++++++- 1 files changed, 56 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c index 3875d49..b2477ca 100644 --- a/kernel/trace/ring_buffer_benchmark.c +++ b/kernel/trace/ring_buffer_benchmark.c @@ -39,6 +39,24 @@ static int write_iteration = 50; module_param(write_iteration, uint, 0644); MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings"); +static int producer_nice = 19; +static int consumer_nice = 19; + +static int producer_fifo = -1; +static int consumer_fifo = -1; + +module_param(producer_nice, uint, 0644); +MODULE_PARM_DESC(producer_nice, "nice prio for producer"); + +module_param(consumer_nice, uint, 0644); +MODULE_PARM_DESC(consumer_nice, "nice prio for consumer"); + +module_param(producer_fifo, uint, 0644); +MODULE_PARM_DESC(producer_fifo, "fifo prio for producer"); + +module_param(consumer_fifo, uint, 0644); +MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer"); + static int read_events; static int kill_test; @@ -270,6 +288,27 @@ static void ring_buffer_producer(void) if (kill_test) trace_printk("ERROR!\n"); + + if (!disable_reader) { + if (consumer_fifo < 0) + trace_printk("Running Consumer at nice: %d\n", + consumer_nice); + else + trace_printk("Running Consumer at SCHED_FIFO %d\n", + consumer_fifo); + } + if (producer_fifo < 0) + trace_printk("Running Producer at nice: %d\n", + producer_nice); + else + trace_printk("Running Producer at SCHED_FIFO %d\n", + producer_fifo); + + /* Let the user know that the test is running at low priority */ + if (producer_fifo < 0 && consumer_fifo < 0 && + producer_nice == 19 && consumer_nice == 19) + trace_printk("WARNING!!! This test is running at lowest priority.\n"); + trace_printk("Time: %lld (usecs)\n", time); trace_printk("Overruns: %lld\n", overruns); if (disable_reader) @@ -402,8 +441,23 @@ static int __init ring_buffer_benchmark_init(void) /* * Run them as low-prio background tasks by default: */ - set_user_nice(consumer, 19); - set_user_nice(producer, 19); + if (!disable_reader) { + if (consumer_fifo >= 0) { + struct sched_param param = { + .sched_priority = consumer_fifo + }; + sched_setscheduler(consumer, SCHED_FIFO, ¶m); + } else + set_user_nice(consumer, consumer_nice); + } + + if (producer_fifo >= 0) { + struct sched_param param = { + .sched_priority = consumer_fifo + }; + sched_setscheduler(producer, SCHED_FIFO, ¶m); + } else + set_user_nice(producer, producer_nice); return 0; -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/