Currently looking at /proc/<pid>/status or statm, there is no way to
distinguish shmem pages from pages mapped to a regular file (shmem
pages are mapped to /dev/zero), even though their implication in
actual memory use is quite different.
This patch adds MM_SHMEMPAGES counter to mm_rss_stat. It keeps track of
resident shmem memory size. Its value is exposed in the new VmShm line
of /proc/<pid>/status.
Signed-off-by: Jerome Marchand <jmarchan@xxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 2 ++
arch/s390/mm/pgtable.c | 2 +-
fs/proc/task_mmu.c | 9 ++++++---
include/linux/mm.h | 7 +++++++
include/linux/mm_types.h | 7 ++++---
kernel/events/uprobes.c | 2 +-
mm/filemap_xip.c | 2 +-
mm/memory.c | 37 +++++++++++++++++++++++++++++++------
mm/rmap.c | 8 ++++----
9 files changed, 57 insertions(+), 19 deletions(-)
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index ddc531a..1c49957 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -171,6 +171,7 @@ read the file /proc/PID/status:
VmLib: 1412 kB
VmPTE: 20 kb
VmSwap: 0 kB
+ VmShm: 0 kB
Threads: 1
SigQ: 0/28578
SigPnd: 0000000000000000
@@ -228,6 +229,7 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
VmLib size of shared library code
VmPTE size of page table entries
VmSwap size of swap usage (the number of referred swapents)
+ VmShm size of resident shmem memory
Threads number of threads
SigQ number of signals queued/max. number for queue
SigPnd bitmap of pending signals for the thread
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 37b8241..9fe31b0 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -612,7 +612,7 @@ static void gmap_zap_swap_entry(swp_entry_t entry, struct mm_struct *mm)
if (PageAnon(page))
dec_mm_counter(mm, MM_ANONPAGES);
else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
}
free_swap_and_cache(entry);
}
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index cfa63ee..4e60751 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -21,7 +21,7 @@
void task_mem(struct seq_file *m, struct mm_struct *mm)
{
- unsigned long data, text, lib, swap;
+ unsigned long data, text, lib, swap, shmem;
unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
/*
@@ -42,6 +42,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
swap = get_mm_counter(mm, MM_SWAPENTS);
+ shmem = get_mm_counter(mm, MM_SHMEMPAGES);
seq_printf(m,
"VmPeak:\t%8lu kB\n"
"VmSize:\t%8lu kB\n"
@@ -54,7 +55,8 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
"VmExe:\t%8lu kB\n"
"VmLib:\t%8lu kB\n"
"VmPTE:\t%8lu kB\n"
- "VmSwap:\t%8lu kB\n",
+ "VmSwap:\t%8lu kB\n"
+ "VmShm:\t%8lu kB\n",
hiwater_vm << (PAGE_SHIFT-10),
total_vm << (PAGE_SHIFT-10),
mm->locked_vm << (PAGE_SHIFT-10),
@@ -65,7 +67,8 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
mm->stack_vm << (PAGE_SHIFT-10), text, lib,
(PTRS_PER_PTE * sizeof(pte_t) *
atomic_long_read(&mm->nr_ptes)) >> 10,
- swap << (PAGE_SHIFT-10));
+ swap << (PAGE_SHIFT-10),
+ shmem << (PAGE_SHIFT-10));
}
unsigned long task_vsize(struct mm_struct *mm)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e03dd29..e69ee9d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1299,6 +1299,13 @@ static inline void dec_mm_counter(struct mm_struct *mm, int member)
atomic_long_dec(&mm->rss_stat.count[member]);
}
+static inline void dec_mm_file_counters(struct mm_struct *mm, struct page *page)
+{
+ dec_mm_counter(mm, MM_FILEPAGES);
+ if (PageSwapBacked(page))
+ dec_mm_counter(mm, MM_SHMEMPAGES);
+}
+
static inline unsigned long get_mm_rss(struct mm_struct *mm)
{
return get_mm_counter(mm, MM_FILEPAGES) +
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 21bff4b..e0307c8 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -322,9 +322,10 @@ struct core_state {
};
enum {
- MM_FILEPAGES,
- MM_ANONPAGES,
- MM_SWAPENTS,
+ MM_FILEPAGES, /* Resident file mapping pages (includes /dev/zero) */
+ MM_ANONPAGES, /* Resident anonymous pages */
+ MM_SWAPENTS, /* Anonymous swap entries */
+ MM_SHMEMPAGES, /* Resident shared memory pages */
NR_MM_COUNTERS
};
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 1d0af8a..6c28c72 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -188,7 +188,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
lru_cache_add_active_or_unevictable(kpage, vma);
if (!PageAnon(page)) {
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
inc_mm_counter(mm, MM_ANONPAGES);
}
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index d8d9fe3..4bd4836 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -194,7 +194,7 @@ retry:
flush_cache_page(vma, address, pte_pfn(*pte));
pteval = ptep_clear_flush(vma, address, pte);
page_remove_rmap(page);
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
BUG_ON(pte_dirty(pteval));
pte_unmap_unlock(pte, ptl);
/* must invalidate_page _before_ freeing the page */
diff --git a/mm/memory.c b/mm/memory.c
index 09e2cd0..c394fc7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -176,6 +176,20 @@ static void check_sync_rss_stat(struct task_struct *task)
#endif /* SPLIT_RSS_COUNTING */
+static void inc_mm_file_counters_fast(struct mm_struct *mm, struct page *page)
+{
+ inc_mm_counter_fast(mm, MM_FILEPAGES);
+ if (PageSwapBacked(page))
+ inc_mm_counter_fast(mm, MM_SHMEMPAGES);
+}
+
+static void dec_mm_file_counters_fast(struct mm_struct *mm, struct page *page)
+{
+ dec_mm_counter_fast(mm, MM_FILEPAGES);
+ if (PageSwapBacked(page))
+ dec_mm_counter_fast(mm, MM_SHMEMPAGES);
+}
+
#ifdef HAVE_GENERIC_MMU_GATHER
static int tlb_next_batch(struct mmu_gather *tlb)
@@ -832,8 +846,11 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
if (PageAnon(page))
rss[MM_ANONPAGES]++;
- else
+ else {
rss[MM_FILEPAGES]++;
+ if (PageSwapBacked(page))
+ rss[MM_SHMEMPAGES]++;
+ }
if (is_write_migration_entry(entry) &&
is_cow_mapping(vm_flags)) {
@@ -875,8 +892,11 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
page_dup_rmap(page);
if (PageAnon(page))
rss[MM_ANONPAGES]++;
- else
+ else {
rss[MM_FILEPAGES]++;
+ if (PageSwapBacked(page))
+ rss[MM_SHMEMPAGES]++;
+ }
}
out_set_pte:
@@ -1140,6 +1160,8 @@ again:
likely(!(vma->vm_flags & VM_SEQ_READ)))
mark_page_accessed(page);
rss[MM_FILEPAGES]--;
+ if (PageSwapBacked(page))
+ rss[MM_SHMEMPAGES]--;
}
page_remove_rmap(page);
if (unlikely(page_mapcount(page) < 0))
@@ -1171,8 +1193,11 @@ again:
if (PageAnon(page))
rss[MM_ANONPAGES]--;
- else
+ else {
rss[MM_FILEPAGES]--;
+ if (PageSwapBacked(page))
+ rss[MM_SHMEMPAGES]--;
+ }
}
if (unlikely(!free_swap_and_cache(entry)))
print_bad_pte(vma, addr, ptent, NULL);
@@ -1495,7 +1520,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
/* Ok, finally just insert the thing.. */
get_page(page);
- inc_mm_counter_fast(mm, MM_FILEPAGES);
+ inc_mm_file_counters_fast(mm, page);
page_add_file_rmap(page);
set_pte_at(mm, addr, pte, mk_pte(page, prot));
@@ -2217,7 +2242,7 @@ gotten:
if (likely(pte_same(*page_table, orig_pte))) {
if (old_page) {
if (!PageAnon(old_page)) {
- dec_mm_counter_fast(mm, MM_FILEPAGES);
+ dec_mm_file_counters_fast(mm, old_page);
inc_mm_counter_fast(mm, MM_ANONPAGES);
}
} else
@@ -2751,7 +2776,7 @@ void do_set_pte(struct vm_area_struct *vma, unsigned long address,
inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
page_add_new_anon_rmap(page, vma, address);
} else {
- inc_mm_counter_fast(vma->vm_mm, MM_FILEPAGES);
+ inc_mm_file_counters_fast(vma->vm_mm, page);
page_add_file_rmap(page);
}
set_pte_at(vma->vm_mm, address, pte, entry);
diff --git a/mm/rmap.c b/mm/rmap.c
index 7928ddd..d40a65b 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1168,7 +1168,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
if (PageAnon(page))
dec_mm_counter(mm, MM_ANONPAGES);
else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
}
set_pte_at(mm, address, pte,
swp_entry_to_pte(make_hwpoison_entry(page)));
@@ -1181,7 +1181,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
if (PageAnon(page))
dec_mm_counter(mm, MM_ANONPAGES);
else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
} else if (PageAnon(page)) {
swp_entry_t entry = { .val = page_private(page) };
pte_t swp_pte;
@@ -1225,7 +1225,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
entry = make_migration_entry(page, pte_write(pteval));
set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
} else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
page_remove_rmap(page);
page_cache_release(page);
@@ -1376,7 +1376,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
page_remove_rmap(page);
page_cache_release(page);
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_file_counters(mm, page);
(*mapcount)--;
}
pte_unmap_unlock(pte - 1, ptl);
--
1.9.3
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