mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smaps
Currently /proc/PID/smaps provides no usage info for vma(VM_HUGETLB),
which is inconvenient when we want to know per-task or per-vma base
hugetlb usage. To solve this, this patch adds new fields for hugetlb
usage like below:
Size: 20480 kB
Rss: 0 kB
Pss: 0 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 0 kB
Private_Dirty: 0 kB
Referenced: 0 kB
Anonymous: 0 kB
AnonHugePages: 0 kB
Shared_Hugetlb: 18432 kB
Private_Hugetlb: 2048 kB
Swap: 0 kB
KernelPageSize: 2048 kB
MMUPageSize: 2048 kB
Locked: 0 kB
VmFlags: rd wr mr mw me de ht
[hughd@google.com: fix Private_Hugetlb alignment ]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Joern Engel <joern@logfs.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 3a9d65c..a7d6c06 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -424,6 +424,9 @@
Private_Dirty: 0 kB
Referenced: 892 kB
Anonymous: 0 kB
+AnonHugePages: 0 kB
+Shared_Hugetlb: 0 kB
+Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
KernelPageSize: 4 kB
@@ -452,6 +455,11 @@
"Swap" shows how much would-be-anonymous memory is also used, but out on
swap.
"SwapPss" shows proportional swap share of this mapping.
+"AnonHugePages" shows the ammount of memory backed by transparent hugepage.
+"Shared_Hugetlb" and "Private_Hugetlb" show the ammounts of memory backed by
+hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical
+reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field.
+
"VmFlags" field deserves a separate description. This member represents the kernel
flags associated with the particular virtual memory area in two letter encoded
manner. The codes are the following:
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index b029d42..5988b83 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -446,6 +446,8 @@
unsigned long anonymous;
unsigned long anonymous_thp;
unsigned long swap;
+ unsigned long shared_hugetlb;
+ unsigned long private_hugetlb;
u64 pss;
u64 swap_pss;
};
@@ -625,12 +627,44 @@
seq_putc(m, '\n');
}
+#ifdef CONFIG_HUGETLB_PAGE
+static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct mem_size_stats *mss = walk->private;
+ struct vm_area_struct *vma = walk->vma;
+ struct page *page = NULL;
+
+ if (pte_present(*pte)) {
+ page = vm_normal_page(vma, addr, *pte);
+ } else if (is_swap_pte(*pte)) {
+ swp_entry_t swpent = pte_to_swp_entry(*pte);
+
+ if (is_migration_entry(swpent))
+ page = migration_entry_to_page(swpent);
+ }
+ if (page) {
+ int mapcount = page_mapcount(page);
+
+ if (mapcount >= 2)
+ mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
+ else
+ mss->private_hugetlb += huge_page_size(hstate_vma(vma));
+ }
+ return 0;
+}
+#endif /* HUGETLB_PAGE */
+
static int show_smap(struct seq_file *m, void *v, int is_pid)
{
struct vm_area_struct *vma = v;
struct mem_size_stats mss;
struct mm_walk smaps_walk = {
.pmd_entry = smaps_pte_range,
+#ifdef CONFIG_HUGETLB_PAGE
+ .hugetlb_entry = smaps_hugetlb_range,
+#endif
.mm = vma->vm_mm,
.private = &mss,
};
@@ -652,6 +686,8 @@
"Referenced: %8lu kB\n"
"Anonymous: %8lu kB\n"
"AnonHugePages: %8lu kB\n"
+ "Shared_Hugetlb: %8lu kB\n"
+ "Private_Hugetlb: %7lu kB\n"
"Swap: %8lu kB\n"
"SwapPss: %8lu kB\n"
"KernelPageSize: %8lu kB\n"
@@ -667,6 +703,8 @@
mss.referenced >> 10,
mss.anonymous >> 10,
mss.anonymous_thp >> 10,
+ mss.shared_hugetlb >> 10,
+ mss.private_hugetlb >> 10,
mss.swap >> 10,
(unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
vma_kernel_pagesize(vma) >> 10,