// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/mm/swap.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 */

/*
 * This file contains the default values for the operation of the
 * Linux VM subsystem. Fine-tuning documentation can be found in
 * Documentation/admin-guide/sysctl/vm.rst.
 * Started 18.12.91
 * Swap aging added 23.2.95, Stephen Tweedie.
 * Buffermem limits added 12.3.98, Rik van Riel.
 */

/* Extracted unchanged from Linux v6.0, mm/swap.c:768-781.
 * Complete function definition; surrounding kernel context is required.
 * Source: https://github.com/torvalds/linux/blob/v6.0/mm/swap.c#L768
 * License text: GPL-2.0.txt (in this directory).
 */
static bool cpu_needs_drain(unsigned int cpu)
{
	struct cpu_fbatches *fbatches = &per_cpu(cpu_fbatches, cpu);

	/* Check these in order of likelihood that they're not zero */
	return folio_batch_count(&fbatches->lru_add) ||
		data_race(folio_batch_count(&per_cpu(lru_rotate.fbatch, cpu))) ||
		folio_batch_count(&fbatches->lru_deactivate_file) ||
		folio_batch_count(&fbatches->lru_deactivate) ||
		folio_batch_count(&fbatches->lru_lazyfree) ||
		folio_batch_count(&fbatches->activate) ||
		need_mlock_page_drain(cpu) ||
		has_bh_in_lru(cpu, NULL);
}