On Tue, Aug 09, 2022 at 12:49:32PM +0300, Alexander Atanasov wrote: > 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); This seems too baroque for my taste. Why not just have two counters for the two pruposes? And is there any value in having this atomic? We want a consistent value but just READ_ONCE seems sufficient ... > 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 > >
