50  * page_counter_cancel - take pages out of the local counter
51  * @counter: counter
54 void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages)  in page_counter_cancel()  argument
58 	new = atomic_long_sub_return(nr_pages, &counter->usage);  in page_counter_cancel()
63 		atomic_long_set(&counter->usage, new);  in page_counter_cancel()
65 	if (track_protection(counter))  in page_counter_cancel()
66 		propagate_protected_usage(counter, new);  in page_counter_cancel()
71  * @counter: counter
74  * NOTE: This does not consider any configured counter limits.
76 void page_counter_charge(struct page_counter *counter, unsigned long nr_pages)  in page_counter_charge()  argument
79 	bool protection = track_protection(counter);  in page_counter_charge()
81 	for (c = counter; c; c = c->parent) {  in page_counter_charge()
111  * @counter: counter
113  * @fail: points first counter to hit its limit, if any
115  * Returns %true on success, or %false and @fail if the counter or one
118 bool page_counter_try_charge(struct page_counter *counter,  in page_counter_try_charge()  argument
123 	bool protection = track_protection(counter);  in page_counter_try_charge()
124 	bool track_failcnt = counter->track_failcnt;  in page_counter_try_charge()
126 	for (c = counter; c; c = c->parent) {  in page_counter_try_charge()
140 		 * counter has changed and retries.  in page_counter_try_charge()
168 	for (c = counter; c != *fail; c = c->parent)  in page_counter_try_charge()
176  * @counter: counter
179 void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages)  in page_counter_uncharge()  argument
183 	for (c = counter; c; c = c->parent)  in page_counter_uncharge()
189  * @counter: counter
193  * counter already exceeds the specified limit.
195  * The caller must serialize invocations on the same counter.
197 int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages)  in page_counter_set_max()  argument
205 		 * below the concurrently-changing counter value.  in page_counter_set_max()
212 		 * modified counter and retry.  in page_counter_set_max()
214 		usage = page_counter_read(counter);  in page_counter_set_max()
219 		old = xchg(&counter->max, nr_pages);  in page_counter_set_max()
221 		if (page_counter_read(counter) <= usage || nr_pages >= old)  in page_counter_set_max()
224 		counter->max = old;  in page_counter_set_max()
231  * @counter: counter
234  * The caller must serialize invocations on the same counter.
236 void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages)  in page_counter_set_min()  argument
240 	WRITE_ONCE(counter->min, nr_pages);  in page_counter_set_min()
242 	for (c = counter; c; c = c->parent)  in page_counter_set_min()
248  * @counter: counter
251  * The caller must serialize invocations on the same counter.
253 void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages)  in page_counter_set_low()  argument
257 	WRITE_ONCE(counter->low, nr_pages);  in page_counter_set_low()
259 	for (c = counter; c; c = c->parent)  in page_counter_set_low()
264  * page_counter_memparse - memparse() for page counter limits
295  * This function calculates an individual page counter's effective
316  *    if one counter claims much more protection than it uses memory,
321  *    budget is NOT proportional. A counter's protection from a sibling
325  *    without having to declare each individual counter's fixed share
328  *    proportion to each counter's *usage*. This makes the protection
416  * @counter: the page_counter the counter to update
425 				       struct page_counter *counter,  in page_counter_calculate_protection()  argument
429 	struct page_counter *parent = counter->parent;  in page_counter_calculate_protection()
438 	if (root == counter)  in page_counter_calculate_protection()
441 	usage = page_counter_read(counter);  in page_counter_calculate_protection()
446 		counter->emin = READ_ONCE(counter->min);  in page_counter_calculate_protection()
447 		counter->elow = READ_ONCE(counter->low);  in page_counter_calculate_protection()
453 	WRITE_ONCE(counter->emin, effective_protection(usage, parent_usage,  in page_counter_calculate_protection()
454 			READ_ONCE(counter->min),  in page_counter_calculate_protection()
459 	WRITE_ONCE(counter->elow, effective_protection(usage, parent_usage,  in page_counter_calculate_protection()
460 			READ_ONCE(counter->low),  in page_counter_calculate_protection()