Re: [PATCH v7 5/7] mm: sched: move NUMA balancing tiering promotion to pghot

From: Donet Tom

Date: Tue May 05 2026 - 00:46:10 EST


Hi Bharata

On 5/4/26 11:39 AM, Bharata B Rao wrote:
+/*
+ * For memory tiering mode, if there are enough free pages (more than
+ * enough watermark defined here) in fast memory node, to take full
+ * advantage of fast memory capacity, all recently accessed slow
+ * memory pages will be migrated to fast memory node without
+ * considering hot threshold.
+ */
+static bool pgdat_free_space_enough(struct pglist_data *pgdat)
+{
+ int z;
+ unsigned long enough_wmark;
+
+ enough_wmark = max(1UL * 1024 * 1024 * 1024 >> PAGE_SHIFT,

Just a thought—would it be better to use #define for these hardcoded values?

-Donet

+ pgdat->node_present_pages >> 4);
+ for (z = pgdat->nr_zones - 1; z >= 0; z--) {