+ mm-vmstat-output-reserved_highatomic-and-free_highatomic-in-zoneinfo.patch added to mm-new branch

+ mm-vmstat-output-reserved_highatomic-and-free_highatomic-in-zoneinfo.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm: vmstat: output reserved_highatomic and free_highatomic in zoneinfo
has been added to the -mm mm-new branch.  Its filename is
     mm-vmstat-output-reserved_highatomic-and-free_highatomic-in-zoneinfo.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmstat-output-reserved_highatomic-and-free_highatomic-in-zoneinfo.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

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------------------------------------------------------
From: Jiayuan Chen <jiayuan.chen@linux.dev>
Subject: mm: vmstat: output reserved_highatomic and free_highatomic in zoneinfo
Date: Mon, 27 Oct 2025 22:18:17 +0800

The nr_free_highatomic is a key factor in calculating watermarks as it
affects the free pages count.  Adding this metric, along with
nr_reserved_highatomic, to /proc/zoneinfo facilitates easier diagnosis
memory watermark calculations and memory pressure states.

Sample output:
cat /proc/zoneinfo
......
pagesets
cpu: 0
		  count:    52069
		  high:     52675
		  batch:    63
		  high_min: 13971
		  high_max: 62284
vm stats threshold: 10
node_unreclaimable:  0
start_pfn:           4096
reserved_highatomic: 5120
free_highatomic:     2081

Link: https://lkml.kernel.org/r/20251027141818.283587-1-jiayuan.chen@linux.dev
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmstat.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/mm/vmstat.c~mm-vmstat-output-reserved_highatomic-and-free_highatomic-in-zoneinfo
+++ a/mm/vmstat.c
@@ -1852,9 +1852,13 @@ static void zoneinfo_show_print(struct s
 	}
 	seq_printf(m,
 		   "\n  node_unreclaimable:  %u"
-		   "\n  start_pfn:           %lu",
+		   "\n  start_pfn:           %lu"
+		   "\n  reserved_highatomic: %lu"
+		   "\n  free_highatomic:     %lu",
 		   atomic_read(&pgdat->kswapd_failures) >= MAX_RECLAIM_RETRIES,
-		   zone->zone_start_pfn);
+		   zone->zone_start_pfn,
+		   zone->nr_reserved_highatomic,
+		   zone->nr_free_highatomic);
 	seq_putc(m, '\n');
 }
 
_

Patches currently in -mm which might be from jiayuan.chen@linux.dev are

mm-vmscan-skip-increasing-kswapd_failures-when-reclaim-was-boosted.patch
mm-vmstat-output-reserved_highatomic-and-free_highatomic-in-zoneinfo.patch