ZONE_DEVICE pages are mapped into a process via the filesystem-dax and
device-dax mechanisms. There are also proposals to use ZONE_DEVICE
pages for other usages outside of dax. Add statistics to smaps so
applications can debug that they are obtaining the mappings they expect,
or otherwise accounting them.
Cc: Christoph Hellwig <h...@lst.de>
Cc: Dave Hansen <dave.han...@intel.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
---
fs/proc/task_mmu.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 35b92d81692f..6765cafcf057 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -445,6 +445,8 @@ struct mem_size_stats {
unsigned long swap;
unsigned long shared_hugetlb;
unsigned long private_hugetlb;
+ unsigned long device;
+ unsigned long device_huge;
u64 pss;
u64 swap_pss;
bool check_shmem_swap;
@@ -458,6 +460,8 @@ static void smaps_account(struct mem_size_stats *mss,
struct page *page,
if (PageAnon(page))
mss->anonymous += size;
+ else if (is_zone_device_page(page))
+ mss->device += size;
mss->resident += size;
/* Accumulate the size in pages that have been accessed. */
@@ -575,7 +579,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
else if (PageSwapBacked(page))
mss->shmem_thp += HPAGE_PMD_SIZE;
else if (is_zone_device_page(page))
- /* pass */;
+ mss->device_huge += HPAGE_PMD_SIZE;
else
VM_BUG_ON_PAGE(1, page);
smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
@@ -774,6 +778,8 @@ static int show_smap(struct seq_file *m, void *v, int
is_pid)
"ShmemPmdMapped: %8lu kB\n"
"Shared_Hugetlb: %8lu kB\n"
"Private_Hugetlb: %7lu kB\n"
+ "Device: %8lu kB\n"
+ "DeviceHugePages: %7lu kB\n"
"Swap: %8lu kB\n"
"SwapPss: %8lu kB\n"
"KernelPageSize: %8lu kB\n"
@@ -792,6 +798,8 @@ static int show_smap(struct seq_file *m, void *v, int
is_pid)
mss.shmem_thp >> 10,
mss.shared_hugetlb >> 10,
mss.private_hugetlb >> 10,
+ mss.device >> 10,
+ mss.device_huge >> 10,
mss.swap >> 10,
(unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)),
vma_kernel_pagesize(vma) >> 10,
