[v3,8/9] mm/page_alloc: make alloc_contig_pages DMB aware

Message ID 20221020215318.4193269-9-opendmb@gmail.com
State New
Headers
Series mm: introduce Designated Movable Blocks |

Commit Message

Doug Berger Oct. 20, 2022, 9:53 p.m. UTC
  Designated Movable Blocks are skipped when attempting to allocate
contiguous pages. Doing per page validation across all spanned
pages within a zone can be extra inefficient when Designated
Movable Blocks create large overlaps between zones. Use
dmb_intersects() within pfn_range_valid_contig as an early check
to signal the range is not valid.

The zone_movable_pfn array which represents the start of non-
overlapped ZONE_MOVABLE on the node is now preserved to be used
at runtime to skip over any DMB-only portion of the zone.

Signed-off-by: Doug Berger <opendmb@gmail.com>
---
 mm/page_alloc.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
  

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 82cad751e0b8..a39eca3bc01b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -437,7 +437,7 @@  static unsigned long required_movablecore __initdata;
 static unsigned long required_movablecore_percent __initdata;
 static unsigned long min_dmb_pfn[MAX_NUMNODES] __initdata;
 static unsigned long max_dmb_pfn[MAX_NUMNODES] __initdata;
-static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
+static unsigned long zone_movable_pfn[MAX_NUMNODES];
 bool mirrored_kernelcore __initdata_memblock;
 
 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
@@ -9460,6 +9460,9 @@  static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
 	unsigned long i, end_pfn = start_pfn + nr_pages;
 	struct page *page;
 
+	if (dmb_intersects(start_pfn, end_pfn))
+		return false;
+
 	for (i = start_pfn; i < end_pfn; i++) {
 		page = pfn_to_online_page(i);
 		if (!page)
@@ -9516,7 +9519,10 @@  struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
 					gfp_zone(gfp_mask), nodemask) {
 		spin_lock_irqsave(&zone->lock, flags);
 
-		pfn = ALIGN(zone->zone_start_pfn, nr_pages);
+		if (zone_idx(zone) == ZONE_MOVABLE && zone_movable_pfn[nid])
+			pfn = ALIGN(zone_movable_pfn[nid], nr_pages);
+		else
+			pfn = ALIGN(zone->zone_start_pfn, nr_pages);
 		while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
 			if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
 				/*