[merged mm-stable] meminfo-add-a-per-node-counter-for-balloon-drivers.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: meminfo: add a per node counter for balloon drivers
has been removed from the -mm tree.  Its filename was
     meminfo-add-a-per-node-counter-for-balloon-drivers.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Nico Pache <npache@redhat.com>
Subject: meminfo: add a per node counter for balloon drivers
Date: Fri, 14 Mar 2025 15:37:54 -0600

Patch series "track memory used by balloon drivers", v2.

This series introduces a way to track memory used by balloon drivers.

Add a NR_BALLOON_PAGES counter to track how many pages are reclaimed by
the balloon drivers.  First add the accounting, then updates the balloon
drivers (virtio, Hyper-V, VMware, Pseries-cmm, and Xen) to maintain this
counter.  The virtio, Vmware, and pseries-cmm balloon drivers utilize the
balloon_compaction interface to allocate and free balloon pages.  Other
balloon drivers will have to maintain this counter manually.

This makes the information visible in memory reporting interfaces like
/proc/meminfo, show_mem, and OOM reporting.

This provides admins visibility into their VM balloon sizes without
requiring different virtualization tooling.  Furthermore, this information
is helpful when debugging an OOM inside a VM.


This patch (of 4):

Add NR_BALLOON_PAGES counter to track memory used by balloon drivers and
expose it through /proc/meminfo and other memory reporting interfaces.

[npache@redhat.com: document Balloon Meminfo entry]
  Link: https://lkml.kernel.org/r/a0315ccf-f244-460e-8643-fd7388724fe5@redhat.com
Link: https://lkml.kernel.org/r/20250314213757.244258-1-npache@redhat.com
Link: https://lkml.kernel.org/r/20250314213757.244258-2-npache@redhat.com
Signed-off-by: Nico Pache <npache@redhat.com>
Cc: Alexander Atanasov <alexander.atanasov@virtuozzo.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Juegren Gross <jgross@suse.com>
Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/filesystems/proc.rst |    3 +++
 fs/proc/meminfo.c                  |    2 ++
 include/linux/mmzone.h             |    1 +
 mm/show_mem.c                      |    4 +++-
 mm/vmstat.c                        |    1 +
 5 files changed, 10 insertions(+), 1 deletion(-)

--- a/Documentation/filesystems/proc.rst~meminfo-add-a-per-node-counter-for-balloon-drivers
+++ a/Documentation/filesystems/proc.rst
@@ -1081,6 +1081,7 @@ Example output. You may not have all of
     FilePmdMapped:         0 kB
     CmaTotal:              0 kB
     CmaFree:               0 kB
+    Balloon:               0 kB
     HugePages_Total:       0
     HugePages_Free:        0
     HugePages_Rsvd:        0
@@ -1255,6 +1256,8 @@ CmaTotal
               Memory reserved for the Contiguous Memory Allocator (CMA)
 CmaFree
               Free remaining memory in the CMA reserves
+Balloon
+              Memory returned to Host by VM Balloon Drivers
 HugePages_Total, HugePages_Free, HugePages_Rsvd, HugePages_Surp, Hugepagesize, Hugetlb
               See Documentation/admin-guide/mm/hugetlbpage.rst.
 DirectMap4k, DirectMap2M, DirectMap1G
--- a/fs/proc/meminfo.c~meminfo-add-a-per-node-counter-for-balloon-drivers
+++ a/fs/proc/meminfo.c
@@ -162,6 +162,8 @@ static int meminfo_proc_show(struct seq_
 	show_val_kb(m, "Unaccepted:     ",
 		    global_zone_page_state(NR_UNACCEPTED));
 #endif
+	show_val_kb(m, "Balloon:        ",
+		    global_node_page_state(NR_BALLOON_PAGES));
 
 	hugetlb_report_meminfo(m);
 
--- a/include/linux/mmzone.h~meminfo-add-a-per-node-counter-for-balloon-drivers
+++ a/include/linux/mmzone.h
@@ -224,6 +224,7 @@ enum node_stat_item {
 #ifdef CONFIG_HUGETLB_PAGE
 	NR_HUGETLB,
 #endif
+	NR_BALLOON_PAGES,
 	NR_VM_NODE_STAT_ITEMS
 };
 
--- a/mm/show_mem.c~meminfo-add-a-per-node-counter-for-balloon-drivers
+++ a/mm/show_mem.c
@@ -260,6 +260,7 @@ static void show_free_areas(unsigned int
 			" pagetables:%lukB"
 			" sec_pagetables:%lukB"
 			" all_unreclaimable? %s"
+			" Balloon:%lukB"
 			"\n",
 			pgdat->node_id,
 			K(node_page_state(pgdat, NR_ACTIVE_ANON)),
@@ -285,7 +286,8 @@ static void show_free_areas(unsigned int
 #endif
 			K(node_page_state(pgdat, NR_PAGETABLE)),
 			K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
-			str_yes_no(pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES));
+			str_yes_no(pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES),
+			K(node_page_state(pgdat, NR_BALLOON_PAGES)));
 	}
 
 	for_each_populated_zone(zone) {
--- a/mm/vmstat.c~meminfo-add-a-per-node-counter-for-balloon-drivers
+++ a/mm/vmstat.c
@@ -1277,6 +1277,7 @@ const char * const vmstat_text[] = {
 #ifdef CONFIG_HUGETLB_PAGE
 	"nr_hugetlb",
 #endif
+	"nr_balloon_pages",
 	/* system-wide enum vm_stat_item counters */
 	"nr_dirty_threshold",
 	"nr_dirty_background_threshold",
_

Patches currently in -mm which might be from npache@redhat.com are