Commit 6af766c8 authored by Jiayuan Chen's avatar Jiayuan Chen Committed by Andrew Morton
Browse files

mm: vmstat: output reserved_highatomic and free_highatomic in zoneinfo 

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: default avatarJiayuan 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 272239dc

mm/vmstat.c

+6 −2
Original line number Diff line number Diff line
@@ -1852,9 +1852,13 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 
	}

	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');

}