mm: show total hugetlb memory consumption in /proc/meminfo
Currently we display some hugepage statistics (total, free, etc) in
/proc/meminfo, but only for default hugepage size (e.g. 2Mb).
If hugepages of different sizes are used (like 2Mb and 1Gb on x86-64),
/proc/meminfo output can be confusing, as non-default sized hugepages
are not reflected at all, and there are no signs that they are existing
and consuming system memory.
To solve this problem, let's display the total amount of memory,
consumed by hugetlb pages of all sized (both free and used). Let's call
it "Hugetlb", and display size in kB to match generic /proc/meminfo
style.
For example, (1024 2Mb pages and 2 1Gb pages are pre-allocated):
$ cat /proc/meminfo
MemTotal: 8168984 kB
MemFree: 3789276 kB
<...>
CmaFree: 0 kB
HugePages_Total: 1024
HugePages_Free: 1024
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 4194304 kB
DirectMap4k: 32632 kB
DirectMap2M: 4161536 kB
DirectMap1G: 6291456 kB
Also, this patch updates corresponding docs to reflect Hugetlb entry
meaning and difference between Hugetlb and HugePages_Total * Hugepagesize.
Link: http://lkml.kernel.org/r/20171115231409.12131-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9a334f5..1e6a5ad 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2975,20 +2975,32 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
void hugetlb_report_meminfo(struct seq_file *m)
{
- struct hstate *h = &default_hstate;
+ struct hstate *h;
+ unsigned long total = 0;
+
if (!hugepages_supported())
return;
- seq_printf(m,
- "HugePages_Total: %5lu\n"
- "HugePages_Free: %5lu\n"
- "HugePages_Rsvd: %5lu\n"
- "HugePages_Surp: %5lu\n"
- "Hugepagesize: %8lu kB\n",
- h->nr_huge_pages,
- h->free_huge_pages,
- h->resv_huge_pages,
- h->surplus_huge_pages,
- 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
+
+ for_each_hstate(h) {
+ unsigned long count = h->nr_huge_pages;
+
+ total += (PAGE_SIZE << huge_page_order(h)) * count;
+
+ if (h == &default_hstate)
+ seq_printf(m,
+ "HugePages_Total: %5lu\n"
+ "HugePages_Free: %5lu\n"
+ "HugePages_Rsvd: %5lu\n"
+ "HugePages_Surp: %5lu\n"
+ "Hugepagesize: %8lu kB\n",
+ count,
+ h->free_huge_pages,
+ h->resv_huge_pages,
+ h->surplus_huge_pages,
+ (PAGE_SIZE << huge_page_order(h)) / 1024);
+ }
+
+ seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024);
}
int hugetlb_report_node_meminfo(int nid, char *buf)