mm: create promo_wmark_pages and clean up open-coded sites

Patch series "mm: print the promo watermark in zoneinfo", v2.


This patch (of 2):

Define promo_wmark_pages and convert current call sites of wmark_pages
with fixed WMARK_PROMO to using it instead.

Link: https://lkml.kernel.org/r/20240801232548.36604-1-kaiyang2@cs.cmu.edu
Link: https://lkml.kernel.org/r/20240801232548.36604-2-kaiyang2@cs.cmu.eduSigned-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/mmzone.h

@@ -669,6 +669,7 @@ enum zone_watermarks {
 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
+#define promo_wmark_pages(z) (z->_watermark[WMARK_PROMO] + z->watermark_boost)
 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
 
 /*

kernel/sched/fair.c

@@ -1742,7 +1742,7 @@ static bool pgdat_free_space_enough(struct pglist_data *pgdat)
 			continue;
 
 		if (zone_watermark_ok(zone, 0,
-				      wmark_pages(zone, WMARK_PROMO) + enough_wmark,
+				      promo_wmark_pages(zone) + enough_wmark,
 				      ZONE_MOVABLE, 0))
 			return true;
 	}

mm/vmscan.c

@@ -6669,7 +6669,7 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int highest_zoneidx)
 			continue;
 
 		if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING)
-			mark = wmark_pages(zone, WMARK_PROMO);
+			mark = promo_wmark_pages(zone);
 		else
 			mark = high_wmark_pages(zone);
 		if (zone_watermark_ok_safe(zone, order, mark, highest_zoneidx))