Merge branch 'cfq-merge' of git://brick.kernel.dk/data/git/linux-2.6-block (7baf398f) · Commits · e / devices / android_kernel_fairphone_FP4

block/cfq-iosched.c

+192 −165

Original line number	Diff line number	Diff line
		@@ -26,18 +26,12 @@ static const int cfq_back_penalty = 2; /* penalty of a backwards seek */
		static const int cfq_slice_sync = HZ / 10;
		static int cfq_slice_async = HZ / 25;
		static const int cfq_slice_async_rq = 2;
		static int cfq_slice_idle = HZ / 100;
		static int cfq_slice_idle = HZ / 70;

		#define CFQ_IDLE_GRACE (HZ / 10)
		#define CFQ_SLICE_SCALE (5)

		#define CFQ_KEY_ASYNC (0)
		#define CFQ_KEY_ANY (0xffff)

		/*
		* disable queueing at the driver/hardware level
		*/
		static const int cfq_max_depth = 2;

		static DEFINE_RWLOCK(cfq_exit_lock);

		@@ -102,6 +96,8 @@ static struct completion *ioc_gone;
		#define cfq_cfqq_sync(cfqq) \
		(cfq_cfqq_class_sync(cfqq) \|\| (cfqq)->on_dispatch[SYNC])

		#define sample_valid(samples) ((samples) > 80)

		/*
		* Per block device queue structure
		*/
		@@ -170,7 +166,6 @@ struct cfq_data {
		unsigned int cfq_slice[2];
		unsigned int cfq_slice_async_rq;
		unsigned int cfq_slice_idle;
		unsigned int cfq_max_depth;

		struct list_head cic_list;
		};
		@@ -343,17 +338,27 @@ static int cfq_queue_empty(request_queue_t *q)
		return !cfqd->busy_queues;
		}

		static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
		{
		if (rw == READ \|\| process_sync(task))
		return task->pid;

		return CFQ_KEY_ASYNC;
		}

		/*
		* Lifted from AS - choose which of crq1 and crq2 that is best served now.
		* We choose the request that is closest to the head right now. Distance
		* behind the head are penalized and only allowed to a certain extent.
		* behind the head is penalized and only allowed to a certain extent.
		*/
		static struct cfq_rq *
		cfq_choose_req(struct cfq_data cfqd, struct cfq_rq crq1, struct cfq_rq *crq2)
		{
		sector_t last, s1, s2, d1 = 0, d2 = 0;
		int r1_wrap = 0, r2_wrap = 0; /* requests are behind the disk head */
		unsigned long back_max;
		#define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */
		#define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */
		unsigned wrap = 0; /* bit mask: requests behind the disk head? */

		if (crq1 == NULL \|\| crq1 == crq2)
		return crq2;
		@@ -385,35 +390,47 @@ cfq_choose_req(struct cfq_data cfqd, struct cfq_rq crq1, struct cfq_rq *crq2)
		else if (s1 + back_max >= last)
		d1 = (last - s1) * cfqd->cfq_back_penalty;
		else
		r1_wrap = 1;
		wrap \|= CFQ_RQ1_WRAP;

		if (s2 >= last)
		d2 = s2 - last;
		else if (s2 + back_max >= last)
		d2 = (last - s2) * cfqd->cfq_back_penalty;
		else
		r2_wrap = 1;
		wrap \|= CFQ_RQ2_WRAP;

		/* Found required data */
		if (!r1_wrap && r2_wrap)

		/*
		* By doing switch() on the bit mask "wrap" we avoid having to
		* check two variables for all permutations: --> faster!
		*/
		switch (wrap) {
		case 0: /* common case for CFQ: crq1 and crq2 not wrapped */
		if (d1 < d2)
		return crq1;
		else if (!r2_wrap && r1_wrap)
		else if (d2 < d1)
		return crq2;
		else if (r1_wrap && r2_wrap) {
		/* both behind the head */
		if (s1 <= s2)
		else {
		if (s1 >= s2)
		return crq1;
		else
		return crq2;
		}

		/* Both requests in front of the head */
		if (d1 < d2)
		case CFQ_RQ2_WRAP:
		return crq1;
		else if (d2 < d1)
		case CFQ_RQ1_WRAP:
		return crq2;
		else {
		if (s1 >= s2)
		case (CFQ_RQ1_WRAP\|CFQ_RQ2_WRAP): /* both crqs wrapped */
		default:
		/*
		* Since both rqs are wrapped,
		* start with the one that's further behind head
		* (--> only one back seek required),
		* since back seek takes more time than forward.
		*/
		if (s1 <= s2)
		return crq1;
		else
		return crq2;
		@@ -612,15 +629,20 @@ cfq_reposition_crq_rb(struct cfq_queue cfqq, struct cfq_rq crq)
		cfq_add_crq_rb(crq);
		}

		static struct request cfq_find_rq_rb(struct cfq_data cfqd, sector_t sector)

		static struct request *
		cfq_find_rq_fmerge(struct cfq_data cfqd, struct bio bio)
		{
		struct cfq_queue *cfqq = cfq_find_cfq_hash(cfqd, current->pid, CFQ_KEY_ANY);
		struct task_struct *tsk = current;
		pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));
		struct cfq_queue *cfqq;
		struct rb_node *n;
		sector_t sector;

		cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
		if (!cfqq)
		goto out;

		sector = bio->bi_sector + bio_sectors(bio);
		n = cfqq->sort_list.rb_node;
		while (n) {
		struct cfq_rq *crq = rb_entry_crq(n);
		@@ -674,7 +696,7 @@ cfq_merge(request_queue_t q, struct request req, struct bio bio)
		goto out;
		}

		__rq = cfq_find_rq_rb(cfqd, bio->bi_sector + bio_sectors(bio));
		__rq = cfq_find_rq_fmerge(cfqd, bio);
		if (__rq && elv_rq_merge_ok(__rq, bio)) {
		ret = ELEVATOR_FRONT_MERGE;
		goto out;
		@@ -877,6 +899,7 @@ static struct cfq_queue cfq_set_active_queue(struct cfq_data cfqd)
		static int cfq_arm_slice_timer(struct cfq_data cfqd, struct cfq_queue cfqq)

		{
		struct cfq_io_context *cic;
		unsigned long sl;

		WARN_ON(!RB_EMPTY(&cfqq->sort_list));
		@@ -892,13 +915,23 @@ static int cfq_arm_slice_timer(struct cfq_data cfqd, struct cfq_queue cfqq)
		/*
		* task has exited, don't wait
		*/
		if (cfqd->active_cic && !cfqd->active_cic->ioc->task)
		cic = cfqd->active_cic;
		if (!cic \|\| !cic->ioc->task)
		return 0;

		cfq_mark_cfqq_must_dispatch(cfqq);
		cfq_mark_cfqq_wait_request(cfqq);

		sl = min(cfqq->slice_end - 1, (unsigned long) cfqd->cfq_slice_idle);

		/*
		* we don't want to idle for seeks, but we do want to allow
		* fair distribution of slice time for a process doing back-to-back
		* seeks. so allow a little bit of time for him to submit a new rq
		*/
		if (sample_valid(cic->seek_samples) && cic->seek_mean > 131072)
		sl = 2;

		mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
		return 1;
		}
		@@ -1115,13 +1148,6 @@ cfq_dispatch_requests(request_queue_t *q, int force)
		if (cfqq) {
		int max_dispatch;

		/*
		* if idle window is disabled, allow queue buildup
		*/
		if (!cfq_cfqq_idle_window(cfqq) &&
		cfqd->rq_in_driver >= cfqd->cfq_max_depth)
		return 0;

		cfq_clear_cfqq_must_dispatch(cfqq);
		cfq_clear_cfqq_wait_request(cfqq);
		del_timer(&cfqd->idle_slice_timer);
		@@ -1171,13 +1197,13 @@ __cfq_find_cfq_hash(struct cfq_data *cfqd, unsigned int key, unsigned int prio,
		const int hashval)
		{
		struct hlist_head *hash_list = &cfqd->cfq_hash[hashval];
		struct hlist_node entry, next;
		struct hlist_node *entry;
		struct cfq_queue *__cfqq;

		hlist_for_each_safe(entry, next, hash_list) {
		struct cfq_queue *__cfqq = list_entry_qhash(entry);
		hlist_for_each_entry(__cfqq, entry, hash_list, cfq_hash) {
		const unsigned short __p = IOPRIO_PRIO_VALUE(__cfqq->org_ioprio_class, __cfqq->org_ioprio);

		if (__cfqq->key == key && (__p == prio \|\| prio == CFQ_KEY_ANY))
		if (__cfqq->key == key && (__p == prio \|\| !prio))
		return __cfqq;
		}

		@@ -1190,19 +1216,19 @@ cfq_find_cfq_hash(struct cfq_data *cfqd, unsigned int key, unsigned short prio)
		return __cfq_find_cfq_hash(cfqd, key, prio, hash_long(key, CFQ_QHASH_SHIFT));
		}

		static void cfq_free_io_context(struct cfq_io_context *cic)
		static void cfq_free_io_context(struct io_context *ioc)
		{
		struct cfq_io_context *__cic;
		struct list_head entry, next;
		int freed = 1;
		struct rb_node *n;
		int freed = 0;

		list_for_each_safe(entry, next, &cic->list) {
		__cic = list_entry(entry, struct cfq_io_context, list);
		while ((n = rb_first(&ioc->cic_root)) != NULL) {
		__cic = rb_entry(n, struct cfq_io_context, rb_node);
		rb_erase(&__cic->rb_node, &ioc->cic_root);
		kmem_cache_free(cfq_ioc_pool, __cic);
		freed++;
		}

		kmem_cache_free(cfq_ioc_pool, cic);
		if (atomic_sub_and_test(freed, &ioc_count) && ioc_gone)
		complete(ioc_gone);
		}
		@@ -1210,8 +1236,7 @@ static void cfq_free_io_context(struct cfq_io_context *cic)
		static void cfq_trim(struct io_context *ioc)
		{
		ioc->set_ioprio = NULL;
		if (ioc->cic)
		cfq_free_io_context(ioc->cic);
		cfq_free_io_context(ioc);
		}

		/*
		@@ -1250,26 +1275,26 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic)
		spin_unlock(q->queue_lock);
		}

		static void cfq_exit_io_context(struct cfq_io_context *cic)
		static void cfq_exit_io_context(struct io_context *ioc)
		{
		struct cfq_io_context *__cic;
		struct list_head *entry;
		unsigned long flags;

		local_irq_save(flags);
		struct rb_node *n;

		/*
		* put the reference this task is holding to the various queues
		*/
		read_lock(&cfq_exit_lock);
		list_for_each(entry, &cic->list) {
		__cic = list_entry(entry, struct cfq_io_context, list);
		read_lock_irqsave(&cfq_exit_lock, flags);

		n = rb_first(&ioc->cic_root);
		while (n != NULL) {
		__cic = rb_entry(n, struct cfq_io_context, rb_node);

		cfq_exit_single_io_context(__cic);
		n = rb_next(n);
		}

		cfq_exit_single_io_context(cic);
		read_unlock(&cfq_exit_lock);
		local_irq_restore(flags);
		read_unlock_irqrestore(&cfq_exit_lock, flags);
		}

		static struct cfq_io_context *
		@@ -1278,10 +1303,10 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
		struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask);

		if (cic) {
		INIT_LIST_HEAD(&cic->list);
		RB_CLEAR(&cic->rb_node);
		cic->key = NULL;
		cic->cfqq[ASYNC] = NULL;
		cic->cfqq[SYNC] = NULL;
		cic->key = NULL;
		cic->last_end_request = jiffies;
		cic->ttime_total = 0;
		cic->ttime_samples = 0;
		@@ -1373,15 +1398,17 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
		static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
		{
		struct cfq_io_context *cic;
		struct rb_node *n;

		write_lock(&cfq_exit_lock);

		cic = ioc->cic;
		n = rb_first(&ioc->cic_root);
		while (n != NULL) {
		cic = rb_entry(n, struct cfq_io_context, rb_node);

		changed_ioprio(cic);

		list_for_each_entry(cic, &cic->list, list)
		changed_ioprio(cic);
		n = rb_next(n);
		}

		write_unlock(&cfq_exit_lock);

		@@ -1445,106 +1472,86 @@ cfq_get_queue(struct cfq_data cfqd, unsigned int key, struct task_struct tsk,
		return cfqq;
		}

		/*
		* Setup general io context and cfq io context. There can be several cfq
		* io contexts per general io context, if this process is doing io to more
		* than one device managed by cfq. Note that caller is holding a reference to
		* cfqq, so we don't need to worry about it disappearing
		*/
		static struct cfq_io_context *
		cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
		cfq_cic_rb_lookup(struct cfq_data cfqd, struct io_context ioc)
		{
		struct io_context *ioc = NULL;
		struct rb_node *n = ioc->cic_root.rb_node;
		struct cfq_io_context *cic;
		void *key = cfqd;

		might_sleep_if(gfp_mask & __GFP_WAIT);
		while (n) {
		cic = rb_entry(n, struct cfq_io_context, rb_node);

		if (key < cic->key)
		n = n->rb_left;
		else if (key > cic->key)
		n = n->rb_right;
		else
		return cic;
		}

		ioc = get_io_context(gfp_mask);
		if (!ioc)
		return NULL;
		}

		restart:
		if ((cic = ioc->cic) == NULL) {
		cic = cfq_alloc_io_context(cfqd, gfp_mask);
		static inline void
		cfq_cic_link(struct cfq_data cfqd, struct io_context ioc,
		struct cfq_io_context *cic)
		{
		struct rb_node **p = &ioc->cic_root.rb_node;
		struct rb_node *parent = NULL;
		struct cfq_io_context *__cic;

		if (cic == NULL)
		goto err;
		read_lock(&cfq_exit_lock);

		/*
		* manually increment generic io_context usage count, it
		* cannot go away since we are already holding one ref to it
		*/
		cic->ioc = ioc;
		cic->key = cfqd;
		read_lock(&cfq_exit_lock);

		ioc->set_ioprio = cfq_ioc_set_ioprio;
		ioc->cic = cic;
		list_add(&cic->queue_list, &cfqd->cic_list);
		read_unlock(&cfq_exit_lock);
		} else {
		struct cfq_io_context *__cic;

		/*
		* the first cic on the list is actually the head itself
		*/
		if (cic->key == cfqd)
		goto out;
		while (*p) {
		parent = *p;
		__cic = rb_entry(parent, struct cfq_io_context, rb_node);

		if (unlikely(!cic->key)) {
		read_lock(&cfq_exit_lock);
		if (list_empty(&cic->list))
		ioc->cic = NULL;
		if (cic->key < __cic->key)
		p = &(*p)->rb_left;
		else if (cic->key > __cic->key)
		p = &(*p)->rb_right;
		else
		ioc->cic = list_entry(cic->list.next,
		struct cfq_io_context,
		list);
		read_unlock(&cfq_exit_lock);
		kmem_cache_free(cfq_ioc_pool, cic);
		atomic_dec(&ioc_count);
		goto restart;
		BUG();
		}

		/*
		* cic exists, check if we already are there. linear search
		* should be ok here, the list will usually not be more than
		* 1 or a few entries long
		*/
		list_for_each_entry(__cic, &cic->list, list) {
		/*
		* this process is already holding a reference to
		* this queue, so no need to get one more
		*/
		if (__cic->key == cfqd) {
		cic = __cic;
		goto out;
		}
		if (unlikely(!__cic->key)) {
		read_lock(&cfq_exit_lock);
		list_del(&__cic->list);
		rb_link_node(&cic->rb_node, parent, p);
		rb_insert_color(&cic->rb_node, &ioc->cic_root);
		list_add(&cic->queue_list, &cfqd->cic_list);
		read_unlock(&cfq_exit_lock);
		kmem_cache_free(cfq_ioc_pool, __cic);
		atomic_dec(&ioc_count);
		goto restart;
		}
		}

		/*
		* nope, process doesn't have a cic assoicated with this
		* cfqq yet. get a new one and add to list
		* Setup general io context and cfq io context. There can be several cfq
		* io contexts per general io context, if this process is doing io to more
		* than one device managed by cfq.
		*/
		__cic = cfq_alloc_io_context(cfqd, gfp_mask);
		if (__cic == NULL)
		goto err;
		static struct cfq_io_context *
		cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
		{
		struct io_context *ioc = NULL;
		struct cfq_io_context *cic;

		__cic->ioc = ioc;
		__cic->key = cfqd;
		read_lock(&cfq_exit_lock);
		list_add(&__cic->list, &cic->list);
		list_add(&__cic->queue_list, &cfqd->cic_list);
		read_unlock(&cfq_exit_lock);
		cic = __cic;
		}
		might_sleep_if(gfp_mask & __GFP_WAIT);

		ioc = get_io_context(gfp_mask);
		if (!ioc)
		return NULL;

		cic = cfq_cic_rb_lookup(cfqd, ioc);
		if (cic)
		goto out;

		cic = cfq_alloc_io_context(cfqd, gfp_mask);
		if (cic == NULL)
		goto err;

		cfq_cic_link(cfqd, ioc, cic);
		out:
		return cic;
		err:
		@@ -1577,7 +1584,33 @@ cfq_update_io_thinktime(struct cfq_data cfqd, struct cfq_io_context cic)
		cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples;
		}

		#define sample_valid(samples) ((samples) > 80)
		static void
		cfq_update_io_seektime(struct cfq_data cfqd, struct cfq_io_context cic,
		struct cfq_rq *crq)
		{
		sector_t sdist;
		u64 total;

		if (cic->last_request_pos < crq->request->sector)
		sdist = crq->request->sector - cic->last_request_pos;
		else
		sdist = cic->last_request_pos - crq->request->sector;

		/*
		* Don't allow the seek distance to get too large from the
		* odd fragment, pagein, etc
		*/
		if (cic->seek_samples <= 60) /* second&third seek */
		sdist = min(sdist, (cic->seek_mean * 4) + 210241024);
		else
		sdist = min(sdist, (cic->seek_mean * 4) + 2102464);

		cic->seek_samples = (7*cic->seek_samples + 256) / 8;
		cic->seek_total = (7cic->seek_total + (u64)256sdist) / 8;
		total = cic->seek_total + (cic->seek_samples/2);
		do_div(total, cic->seek_samples);
		cic->seek_mean = (sector_t)total;
		}

		/*
		* Disable idle window if the process thinks too long or seeks so much that
		@@ -1690,9 +1723,11 @@ cfq_crq_enqueued(struct cfq_data cfqd, struct cfq_queue cfqq,
		cic = crq->io_context;

		cfq_update_io_thinktime(cfqd, cic);
		cfq_update_io_seektime(cfqd, cic, crq);
		cfq_update_idle_window(cfqd, cfqq, cic);

		cic->last_queue = jiffies;
		cic->last_request_pos = crq->request->sector + crq->request->nr_sectors;

		if (cfqq == cfqd->active_queue) {
		/*
		@@ -1825,14 +1860,6 @@ static void cfq_prio_boost(struct cfq_queue *cfqq)
		cfq_resort_rr_list(cfqq, 0);
		}

		static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
		{
		if (rw == READ \|\| process_sync(task))
		return task->pid;

		return CFQ_KEY_ASYNC;
		}

		static inline int
		__cfq_may_queue(struct cfq_data cfqd, struct cfq_queue cfqq,
		struct task_struct *task, int rw)
		@@ -1965,7 +1992,7 @@ cfq_set_request(request_queue_t q, struct request rq, struct bio *bio,

		might_sleep_if(gfp_mask & __GFP_WAIT);

		cic = cfq_get_io_context(cfqd, key, gfp_mask);
		cic = cfq_get_io_context(cfqd, gfp_mask);

		spin_lock_irqsave(q->queue_lock, flags);

		@@ -2133,10 +2160,13 @@ static void cfq_exit_queue(elevator_t *e)
		request_queue_t *q = cfqd->queue;

		cfq_shutdown_timer_wq(cfqd);

		write_lock(&cfq_exit_lock);
		spin_lock_irq(q->queue_lock);

		if (cfqd->active_queue)
		__cfq_slice_expired(cfqd, cfqd->active_queue, 0);

		while (!list_empty(&cfqd->cic_list)) {
		struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
		struct cfq_io_context,
		@@ -2152,6 +2182,7 @@ static void cfq_exit_queue(elevator_t *e)
		cic->key = NULL;
		list_del_init(&cic->queue_list);
		}

		spin_unlock_irq(q->queue_lock);
		write_unlock(&cfq_exit_lock);

		@@ -2227,7 +2258,6 @@ static int cfq_init_queue(request_queue_t q, elevator_t e)
		cfqd->cfq_slice[1] = cfq_slice_sync;
		cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
		cfqd->cfq_slice_idle = cfq_slice_idle;
		cfqd->cfq_max_depth = cfq_max_depth;

		return 0;
		out_crqpool:
		@@ -2310,7 +2340,6 @@ SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1);
		SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
		SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
		SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
		SHOW_FUNCTION(cfq_max_depth_show, cfqd->cfq_max_depth, 0);
		#undef SHOW_FUNCTION

		#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
		@@ -2339,7 +2368,6 @@ STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1);
		STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1);
		STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
		STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, UINT_MAX, 0);
		STORE_FUNCTION(cfq_max_depth_store, &cfqd->cfq_max_depth, 1, UINT_MAX, 0);
		#undef STORE_FUNCTION

		#define CFQ_ATTR(name) \
		@@ -2356,7 +2384,6 @@ static struct elv_fs_entry cfq_attrs[] = {
		CFQ_ATTR(slice_async),
		CFQ_ATTR(slice_async_rq),
		CFQ_ATTR(slice_idle),
		CFQ_ATTR(max_depth),
		__ATTR_NULL
		};

block/ll_rw_blk.c

+15 −6

Original line number	Diff line number	Diff line
		@@ -3539,11 +3539,17 @@ void put_io_context(struct io_context *ioc)
		BUG_ON(atomic_read(&ioc->refcount) == 0);

		if (atomic_dec_and_test(&ioc->refcount)) {
		struct cfq_io_context *cic;

		rcu_read_lock();
		if (ioc->aic && ioc->aic->dtor)
		ioc->aic->dtor(ioc->aic);
		if (ioc->cic && ioc->cic->dtor)
		ioc->cic->dtor(ioc->cic);
		if (ioc->cic_root.rb_node != NULL) {
		struct rb_node *n = rb_first(&ioc->cic_root);

		cic = rb_entry(n, struct cfq_io_context, rb_node);
		cic->dtor(ioc);
		}
		rcu_read_unlock();

		kmem_cache_free(iocontext_cachep, ioc);
		@@ -3556,6 +3562,7 @@ void exit_io_context(void)
		{
		unsigned long flags;
		struct io_context *ioc;
		struct cfq_io_context *cic;

		local_irq_save(flags);
		task_lock(current);
		@@ -3567,8 +3574,10 @@ void exit_io_context(void)

		if (ioc->aic && ioc->aic->exit)
		ioc->aic->exit(ioc->aic);
		if (ioc->cic && ioc->cic->exit)
		ioc->cic->exit(ioc->cic);
		if (ioc->cic_root.rb_node != NULL) {
		cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
		cic->exit(ioc);
		}

		put_io_context(ioc);
		}
		@@ -3598,7 +3607,7 @@ struct io_context *current_io_context(gfp_t gfp_flags)
		ret->last_waited = jiffies; /* doesn't matter... */
		ret->nr_batch_requests = 0; /* because this is 0 */
		ret->aic = NULL;
		ret->cic = NULL;
		ret->cic_root.rb_node = NULL;
		tsk->io_context = ret;
		}

include/linux/blkdev.h

+13 −9

Original line number	Diff line number	Diff line
		@@ -55,25 +55,29 @@ struct as_io_context {

		struct cfq_queue;
		struct cfq_io_context {
		/*
		* circular list of cfq_io_contexts belonging to a process io context
		*/
		struct list_head list;
		struct cfq_queue *cfqq[2];
		struct rb_node rb_node;
		void *key;

		struct cfq_queue *cfqq[2];

		struct io_context *ioc;

		unsigned long last_end_request;
		sector_t last_request_pos;
		unsigned long last_queue;

		unsigned long ttime_total;
		unsigned long ttime_samples;
		unsigned long ttime_mean;

		unsigned int seek_samples;
		u64 seek_total;
		sector_t seek_mean;

		struct list_head queue_list;

		void (dtor)(struct cfq_io_context );
		void (exit)(struct cfq_io_context );
		void (dtor)(struct io_context ); /* destructor */
		void (exit)(struct io_context ); /* called on task exit */
		};

		/*
		@@ -94,7 +98,7 @@ struct io_context {
		int nr_batch_requests; /* Number of requests left in the batch */

		struct as_io_context *aic;
		struct cfq_io_context *cic;
		struct rb_root cic_root;
		};

		void put_io_context(struct io_context *ioc);