linux-master/mm/page_counter.c

47  * @nr_pages: number of pages to cancel
49 void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages)
53 	new = atomic_long_sub_return(nr_pages, &counter->usage);
55 	if (WARN_ONCE(new < 0, "page_counter underflow: %ld nr_pages=%lu\n",
56 		      new, nr_pages)) {
66  * @nr_pages: number of pages to charge
70 void page_counter_charge(struct page_counter *counter, unsigned long nr_pages)
77 		new = atomic_long_add_return(nr_pages, &c->usage);
91  * @nr_pages: number of pages to charge
98 			     unsigned long nr_pages,
119 		new = atomic_long_add_return(nr_pages, &c->usage);
121 			atomic_long_sub(nr_pages, &c->usage);
143 		page_counter_cancel(c, nr_pages);
151  * @nr_pages: number of pages to uncharge
153 void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages)
158 		page_counter_cancel(c, nr_pages);
164  * @nr_pages: limit to set
171 int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages)
190 		if (usage > nr_pages)
193 		old = xchg(&counter->max, nr_pages);
195 		if (page_counter_read(counter) <= usage || nr_pages >= old)
206  * @nr_pages: value to set
210 void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages)
214 	WRITE_ONCE(counter->min, nr_pages);
223  * @nr_pages: value to set
227 void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages)
231 	WRITE_ONCE(counter->low, nr_pages);
241  * @nr_pages: returns the result in number of pages
243  * Returns -EINVAL, or 0 and @nr_pages on success.  @nr_pages will be
247 			  unsigned long *nr_pages)
253 		*nr_pages = PAGE_COUNTER_MAX;
261 	*nr_pages = min(bytes / PAGE_SIZE, (u64)PAGE_COUNTER_MAX);