dm cache: add io_tracker (77289d32) · Commits · 戴 / test

drivers/md/dm-cache-target.c

+73 −0

Original line number	Original line	Diff line number	Diff line
	@@ -25,6 +25,79 @@ DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle,

	/----------------------------------------------------------------/		/----------------------------------------------------------------/

			#define IOT_RESOLUTION 4

			struct io_tracker {
			spinlock_t lock;

			/*
			* Sectors of in-flight IO.
			*/
			sector_t in_flight;

			/*
			* The time, in jiffies, when this device became idle (if it is
			* indeed idle).
			*/
			unsigned long idle_time;
			unsigned long last_update_time;
			};

			static void iot_init(struct io_tracker *iot)
			{
			spin_lock_init(&iot->lock);
			iot->in_flight = 0ul;
			iot->idle_time = 0ul;
			iot->last_update_time = jiffies;
			}

			static bool __iot_idle_for(struct io_tracker *iot, unsigned long jifs)
			{
			if (iot->in_flight)
			return false;

			return time_after(jiffies, iot->idle_time + jifs);
			}

			static bool iot_idle_for(struct io_tracker *iot, unsigned long jifs)
			{
			bool r;
			unsigned long flags;

			spin_lock_irqsave(&iot->lock, flags);
			r = __iot_idle_for(iot, jifs);
			spin_unlock_irqrestore(&iot->lock, flags);

			return r;
			}

			static void iot_io_begin(struct io_tracker *iot, sector_t len)
			{
			unsigned long flags;

			spin_lock_irqsave(&iot->lock, flags);
			iot->in_flight += len;
			spin_unlock_irqrestore(&iot->lock, flags);
			}

			static void __iot_io_end(struct io_tracker *iot, sector_t len)
			{
			iot->in_flight -= len;
			if (!iot->in_flight)
			iot->idle_time = jiffies;
			}

			static void iot_io_end(struct io_tracker *iot, sector_t len)
			{
			unsigned long flags;

			spin_lock_irqsave(&iot->lock, flags);
			__iot_io_end(iot, len);
			spin_unlock_irqrestore(&iot->lock, flags);
			}

			/----------------------------------------------------------------/

	/*		/*
	* Glossary:		* Glossary:
	*		*

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