Display reported in /proc/meminfo as:
Inflated(total) or Inflated(free)
depending on the driver.
Drivers use the sign bit to indicate where they do account
the inflated memory.
Amount of inflated memory can be used by:
- as a hint for the oom a killer
- user space software that monitors memory pressure
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Wei Liu <wei.liu@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Signed-off-by: Alexander Atanasov <alexander.atanasov@xxxxxxxxxxxxx>
---
Documentation/filesystems/proc.rst | 5 +++++
fs/proc/meminfo.c | 11 +++++++++++
include/linux/mm.h | 4 ++++
mm/page_alloc.c | 4 ++++
4 files changed, 24 insertions(+)
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 1bc91fb8c321..064b5b3d5bd8 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -986,6 +986,7 @@ Example output. You may not have all of these fields.
VmallocUsed: 40444 kB
VmallocChunk: 0 kB
Percpu: 29312 kB
+ Inflated(total): 2097152 kB
HardwareCorrupted: 0 kB
AnonHugePages: 4149248 kB
ShmemHugePages: 0 kB
@@ -1133,6 +1134,10 @@ VmallocChunk
Percpu
Memory allocated to the percpu allocator used to back percpu
allocations. This stat excludes the cost of metadata.
+Inflated(total) or Inflated(free)
+ Amount of memory that is inflated by the balloon driver.
+ Due to differences among balloon drivers inflated memory
+ is either subtracted from TotalRam or from MemFree.
HardwareCorrupted
The amount of RAM/memory in KB, the kernel identifies as
corrupted.
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 6e89f0e2fd20..ebbe52ccbb93 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -38,6 +38,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
unsigned long pages[NR_LRU_LISTS];
unsigned long sreclaimable, sunreclaim;
int lru;
+#ifdef CONFIG_MEMORY_BALLOON
+ long inflated_kb;
+#endif
si_meminfo(&i);
si_swapinfo(&i);
@@ -153,6 +156,14 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
global_zone_page_state(NR_FREE_CMA_PAGES));
#endif
+#ifdef CONFIG_MEMORY_BALLOON
+ inflated_kb = atomic_long_read(&mem_balloon_inflated_kb);
+ if (inflated_kb >= 0)
+ seq_printf(m, "Inflated(total): %8ld kB\n", inflated_kb);
+ else
+ seq_printf(m, "Inflated(free): %8ld kB\n", -inflated_kb);
+#endif
+
hugetlb_report_meminfo(m);
arch_report_meminfo(m);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7898e29bcfb5..b190811dc16e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2582,6 +2582,10 @@ extern int watermark_boost_factor;
extern int watermark_scale_factor;
extern bool arch_has_descending_max_zone_pfns(void);
+#ifdef CONFIG_MEMORY_BALLOON
+extern atomic_long_t mem_balloon_inflated_kb;
+#endif
+
/* nommu.c */
extern atomic_long_t mmap_pages_allocated;
extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b0bcab50f0a3..12359179a3a2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -194,6 +194,10 @@ EXPORT_SYMBOL(init_on_alloc);
DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
EXPORT_SYMBOL(init_on_free);
+#ifdef CONFIG_MEMORY_BALLOON
+atomic_long_t mem_balloon_inflated_kb = ATOMIC_LONG_INIT(0);
+#endif
+
static bool _init_on_alloc_enabled_early __read_mostly
= IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON);
static int __init early_init_on_alloc(char *buf)
--
2.31.1
