bcache: introduce force_wake_up_gc() (cb07ad63) · Commits · 戴 / test

drivers/md/bcache/btree.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -266,6 +266,24 @@ static inline void wake_up_gc(struct cache_set *c)
		wake_up(&c->gc_wait);
		}

		static inline void force_wake_up_gc(struct cache_set *c)
		{
		/*
		* Garbage collection thread only works when sectors_to_gc < 0,
		* calling wake_up_gc() won't start gc thread if sectors_to_gc is
		* not a nagetive value.
		* Therefore sectors_to_gc is set to -1 here, before waking up
		* gc thread by calling wake_up_gc(). Then gc_should_run() will
		* give a chance to permit gc thread to run. "Give a chance" means
		* before going into gc_should_run(), there is still possibility
		* that c->sectors_to_gc being set to other positive value. So
		* this routine won't 100% make sure gc thread will be woken up
		* to run.
		*/
		atomic_set(&c->sectors_to_gc, -1);
		wake_up_gc(c);
		}

		#define MAP_DONE 0
		#define MAP_CONTINUE 1

+2 −15

Original line number	Diff line number	Diff line
		@@ -742,21 +742,8 @@ STORE(__bch_cache_set)
		bch_cache_accounting_clear(&c->accounting);
		}

		if (attr == &sysfs_trigger_gc) {
		/*
		* Garbage collection thread only works when sectors_to_gc < 0,
		* when users write to sysfs entry trigger_gc, most of time
		* they want to forcibly triger gargage collection. Here -1 is
		* set to c->sectors_to_gc, to make gc_should_run() give a
		* chance to permit gc thread to run. "give a chance" means
		* before going into gc_should_run(), there is still chance
		* that c->sectors_to_gc being set to other positive value. So
		* writing sysfs entry trigger_gc won't always make sure gc
		* thread takes effect.
		*/
		atomic_set(&c->sectors_to_gc, -1);
		wake_up_gc(c);
		}
		if (attr == &sysfs_trigger_gc)
		force_wake_up_gc(c);

		if (attr == &sysfs_prune_cache) {
		struct shrink_control sc;