Many works will go to submit_bio(), and in many cases the io priority of
kworker cannot meet the real-time requirements of this work.
So add the basic attribute ioprio to work_struct, and kworker can adjust
its io priority according to this attribute.
Add function set_work_ioprio() to set the io priority of this work.
Add function may_adjust_work_task_ioprio() to adjust kworker's io priority.
Add function restore_work_task_ioprio() to restore kworker's io priority.
Signed-off-by: Yi Sun <yi....@unisoc.com>
---
include/linux/workqueue.h | 9 ++++++
include/linux/workqueue_types.h | 6 ++++
kernel/workqueue.c | 51 +++++++++++++++++++++++++++++++++
3 files changed, 66 insertions(+)
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index fb3993894536..f6191774b730 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -286,6 +286,9 @@ static inline unsigned int work_static(struct work_struct
*work) { return 0; }
lockdep_init_map(&(_work)->lockdep_map,
"(work_completion)"#_work, (_key), 0); \
INIT_LIST_HEAD(&(_work)->entry); \
(_work)->func = (_func); \
+ (_work)->ioprio = 0; \
+ (_work)->ori_ioprio = 0; \
+ (_work)->ioprio_flag = 0; \
} while (0)
#else
#define __INIT_WORK_KEY(_work, _func, _onstack, _key) \
@@ -294,6 +297,9 @@ static inline unsigned int work_static(struct work_struct
*work) { return 0; }
(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
INIT_LIST_HEAD(&(_work)->entry); \
(_work)->func = (_func); \
+ (_work)->ioprio = 0; \
+ (_work)->ori_ioprio = 0; \
+ (_work)->ioprio_flag = 0; \
} while (0)
#endif
@@ -585,6 +591,9 @@ extern struct work_struct *current_work(void);
extern bool current_is_workqueue_rescuer(void);
extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
extern unsigned int work_busy(struct work_struct *work);
+extern void set_work_ioprio(struct work_struct *work, unsigned short ioprio);
+extern void may_adjust_work_task_ioprio(struct work_struct *work);
+extern void restore_work_task_ioprio(struct work_struct *work);
extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
extern void print_worker_info(const char *log_lvl, struct task_struct *task);
extern void show_all_workqueues(void);
diff --git a/include/linux/workqueue_types.h b/include/linux/workqueue_types.h
index 4c38824f3ab4..d9969596bbc3 100644
--- a/include/linux/workqueue_types.h
+++ b/include/linux/workqueue_types.h
@@ -17,6 +17,12 @@ struct work_struct {
atomic_long_t data;
struct list_head entry;
work_func_t func;
+ /* If the work does submit_bio, io priority may be needed. */
+ unsigned short ioprio;
+ /* Record kworker's original io priority. */
+ unsigned short ori_ioprio;
+ /* Whether the work has set io priority? */
+ long ioprio_flag;
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 003474c9a77d..a44a8f92eec2 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -55,6 +55,7 @@
#include <linux/kvm_para.h>
#include <linux/delay.h>
#include <linux/irq_work.h>
+#include <linux/ioprio.h>
#include "workqueue_internal.h"
@@ -6025,6 +6026,56 @@ unsigned int work_busy(struct work_struct *work)
}
EXPORT_SYMBOL_GPL(work_busy);
+/**
+ * set_work_ioprio - set io priority for the current work
+ * @work: the work to be set
+ * @ioprio: desired io priority
+ *
+ * This function can be called after INIT_WORK if the io priority
+ * of the work needs to adjust. And it is recommended to use this
+ * function together with may_adjust_work_task_ioprio() and
+ * restore_work_task_ioprio().
+ */
+void set_work_ioprio(struct work_struct *work, unsigned short ioprio)
+{
+ work->ioprio = ioprio;
+ work->ioprio_flag = 1;
+}
+EXPORT_SYMBOL_GPL(set_work_ioprio);
+
+/**
+ * may_adjust_work_task_ioprio - adjust the io priority of kworker
+ * @work: the work that kworker will do
+ *
+ * It is recommended to use this function together with set_work_ioprio()
+ * and restore_work_task_ioprio().
+ */
+void may_adjust_work_task_ioprio(struct work_struct *work)
+{
+ if (work->ioprio_flag) {
+ work->ori_ioprio = get_current_ioprio();
+ set_task_ioprio(current, work->ioprio);
+ }
+}
+EXPORT_SYMBOL_GPL(may_adjust_work_task_ioprio);
+
+/**
+ * restore_work_task_ioprio - restore the io priority of kworker
+ * @work: the work that kworker just did
+ *
+ * When kworker finishes the work, the original io priority of
+ * kworker should be restored. It is recommended to use this function
+ * together with set_work_ioprio() and may_adjust_work_task_ioprio().
+ */
+void restore_work_task_ioprio(struct work_struct *work)
+{
+ if (work->ioprio_flag) {
+ set_task_ioprio(current, work->ori_ioprio);
+ work->ioprio_flag = 0;
+ }
+}
+EXPORT_SYMBOL_GPL(restore_work_task_ioprio);
+
/**
* set_worker_desc - set description for the current work item
* @fmt: printf-style format string
--
2.25.1
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