// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Swap reorganised 29.12.95, Stephen Tweedie.
 *  kswapd added: 7.1.96  sct
 *  Removed kswapd_ctl limits, and swap out as many pages as needed
 *  to bring the system back to freepages.high: 2.4.97, Rik van Riel.
 *  Zone aware kswapd started 02/00, Kanoj Sarcar (kanoj@sgi.com).
 *  Multiqueue VM started 5.8.00, Rik van Riel.
 */

/* Extracted unchanged from Linux v6.12, mm/vmscan.c:7060-7066.
 * Full function definition; surrounding kernel context is required.
 * Source: https://github.com/torvalds/linux/blob/v6.12/mm/vmscan.c#L7060
 * License text: GPL-2.0.txt (in this directory).
 */
static enum zone_type kswapd_highest_zoneidx(pg_data_t *pgdat,
					   enum zone_type prev_highest_zoneidx)
{
	enum zone_type curr_idx = READ_ONCE(pgdat->kswapd_highest_zoneidx);

	return curr_idx == MAX_NR_ZONES ? prev_highest_zoneidx : curr_idx;
}