This is an odd module which speeds up hackbench test. It tries to behave like /drivers/thermal subsystem with a container thermal zone looping over normal thermal zones.
Test description: - run hackbench on ARM64 with big.LITTLE: $ ./hackbench 100 process 100
- then load this module $ insmod ./hackbench_speedup.ko
- then run hackbench once again $ ./hackbench 100 process 100
- unload the module, you can run the hackbench after that and the result will be the same (shorter time) $ rmmod hackbench_speedup
Some results captured on my ARM64 (4big + 4LITTLE) machine: root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 11.207 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 11.029 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 11.452 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 10.522 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 12.044 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 11.532 root@draco:~# root@draco:~# insmod ./hackbench_speedup.ko root@draco:~# root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 6.474 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 6.477 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 6.294 root@draco:~# /root/devlib-target/hackbench 100 process 100 Running with 100*40 (== 4000) tasks. Time: 6.237
Signed-off-by: Lukasz Luba l.luba@partner.samsung.com --- drivers/base/hackbench_speedup.c | 148 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 drivers/base/hackbench_speedup.c
diff --git a/drivers/base/hackbench_speedup.c b/drivers/base/hackbench_speedup.c new file mode 100644 index 0000000..952df47 --- /dev/null +++ b/drivers/base/hackbench_speedup.c @@ -0,0 +1,148 @@ + + +#define pr_fmt(fmt) "HACKBENCH: " fmt + +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/workqueue.h> + +#define POLLING_DELAY 1000 + +struct task_data { + int id; + struct delayed_work wq; + struct mutex lock; + int polling_delay; + struct list_head node; + struct list_head subtasks; + bool container; + int (*get_status)(struct task_data *td); +}; + + +static LIST_HEAD(tasks_list); +static DEFINE_MUTEX(tasks_list_lock); + + +static int task_container_status(struct task_data *master) +{ + struct task_data *td; + + pr_info("container task status\n"); + + if (!master || !master->container) + return -EINVAL; + + if (list_empty(&master->subtasks)) + return -EINVAL; + + list_for_each_entry(td, &master->subtasks, subtasks) { + mutex_lock(&td->lock); + /* get status */ + mutex_unlock(&td->lock); + } + + + return 0; +} + +static int task_status(struct task_data *td) +{ + pr_info("single task status\n"); + + return 0; +} + +static void task_status_check(struct work_struct *work) +{ + int ret; + struct task_data *td = container_of(work, struct task_data, wq.work); + + if (!td->get_status) + return; + + mutex_lock(&td->lock); + ret = td->get_status(td); + mutex_unlock(&td->lock); + + mod_delayed_work(system_freezable_wq, &td->wq, + msecs_to_jiffies(POLLING_DELAY)); +} + +static int __init task_status_init(void) +{ + int i; + struct task_data *task; + struct task_data *master; + int total_tasks = 4; + + task = kzalloc(sizeof(struct task_data), GFP_KERNEL); + if (!task) + return -ENOMEM; + + INIT_LIST_HEAD(&task->subtasks); + task->container = true; + + mutex_lock(&tasks_list_lock); + list_add_tail(&task->node, &tasks_list); + mutex_unlock(&tasks_list_lock); + + INIT_DELAYED_WORK(&task->wq, task_status_check); + + master = task; + master->get_status = task_container_status; + + for (i = 1; i < total_tasks; i++) { + + task = kzalloc(sizeof(struct task_data), GFP_KERNEL); + if (!task) + goto clean; + + mutex_lock(&tasks_list_lock); + list_add_tail(&task->node, &tasks_list); + mutex_unlock(&tasks_list_lock); + + INIT_DELAYED_WORK(&task->wq, task_status_check); + + list_add_tail(&task->subtasks, &master->subtasks); + + task->get_status = task_status; + + mod_delayed_work(system_freezable_wq, &task->wq, + msecs_to_jiffies(POLLING_DELAY)); + } + + mod_delayed_work(system_freezable_wq, &master->wq, + msecs_to_jiffies(POLLING_DELAY)); + + return 0; + +clean: + return -ENOMEM; +} + + +static void __exit task_exit(void) +{ + struct task_data *td, *tmp; + + list_for_each_entry_safe(td, tmp, &tasks_list, node) { + mutex_lock(&td->lock); + cancel_delayed_work(&td->wq); + mutex_unlock(&td->lock); + + list_del(&td->node); + kfree(td); + } + + mutex_destroy(&tasks_list_lock); +} + +module_init(task_status_init); +module_exit(task_exit); + +MODULE_AUTHOR("Lukasz Luba l.luba@partner.samsung.com"); +MODULE_DESCRIPTION("Test module which shows speed up in hackbench"); +MODULE_VERSION("1.0"); +MODULE_LICENSE("GPL"); -- 2.7.4
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Lukasz Luba