From: Nico Pache Date: Fri, 14 Mar 2025 21:37:54 +0000 (-0600) Subject: meminfo: add a per node counter for balloon drivers X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=835de37603ef6412949df0a607128f5fffed4576;p=users%2Fjedix%2Flinux-maple.git meminfo: add a per node counter for balloon drivers 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 Cc: Alexander Atanasov Cc: Chengming Zhou Cc: David Hildenbrand Cc: Dexuan Cui Cc: Haiyang Zhang Cc: Johannes Weiner Cc: Juegren Gross Cc: Kanchana P Sridhar Cc: K. Y. Srinivasan Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Muchun Song Cc: Nhat Pham Cc: Oleksandr Tyshchenko Cc: Roman Gushchin Cc: Shakeel Butt Cc: Stefano Stabellini Cc: Wei Liu Cc: Michael Kelley Signed-off-by: Andrew Morton --- diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 3c37b248fc4f1..80f33bce5fe19 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -1081,6 +1081,7 @@ Example output. You may not have all of these fields. 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 diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 8ba9b14723902..83be312159c98 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -162,6 +162,8 @@ static int meminfo_proc_show(struct seq_file *m, void *v) 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); diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 37c29f3fbca83..a9db0fbd2b941 100644 --- a/include/linux/mmzone.h +++ b/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 }; diff --git a/mm/show_mem.c b/mm/show_mem.c index 43afb56abbd3e..6af13bcd2ab36 100644 --- a/mm/show_mem.c +++ b/mm/show_mem.c @@ -260,6 +260,7 @@ static void show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_z " 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 filter, nodemask_t *nodemask, int max_z #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) { diff --git a/mm/vmstat.c b/mm/vmstat.c index ed49a86348f7a..ae0e4259ac236 100644 --- a/mm/vmstat.c +++ b/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",