From: Jerome Marchand <jmarchan@xxxxxxxxxx>
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 to account for
shmem pages instead of MM_FILEPAGES.
Signed-off-by: Jerome Marchand <jmarchan@xxxxxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
arch/s390/mm/pgtable.c | 5 +----
fs/proc/task_mmu.c | 3 ++-
include/linux/mm.h | 28 ++++++++++++++++++++++++++++
include/linux/mm_types.h | 9 ++++++---
kernel/events/uprobes.c | 2 +-
mm/memory.c | 30 ++++++++++--------------------
mm/oom_kill.c | 5 +++--
mm/rmap.c | 15 ++++-----------
8 files changed, 55 insertions(+), 42 deletions(-)
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index b2c1542..5bffd5d 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -617,10 +617,7 @@ static void gmap_zap_swap_entry(swp_entry_t entry, struct mm_struct *mm)
else if (is_migration_entry(entry)) {
struct page *page = migration_entry_to_page(entry);
- if (PageAnon(page))
- dec_mm_counter(mm, MM_ANONPAGES);
- else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_counter(mm, mm_counter(page));
}
free_swap_and_cache(entry);
}
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 1b271ec..e86e137 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -81,7 +81,8 @@ unsigned long task_statm(struct mm_struct *mm,
unsigned long *shared, unsigned long *text,
unsigned long *data, unsigned long *resident)
{
- *shared = get_mm_counter(mm, MM_FILEPAGES);
+ *shared = get_mm_counter(mm, MM_FILEPAGES) +
+ get_mm_counter(mm, MM_SHMEMPAGES);
*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
>> PAGE_SHIFT;
*data = mm->total_vm - mm->shared_vm;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 47a9392..adfbb5b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1364,6 +1364,16 @@ static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
return (unsigned long)val;
}
+/* A wrapper for the CONFIG_SHMEM dependent counter */
+static inline unsigned long get_mm_counter_shmem(struct mm_struct *mm)
+{
+#ifdef CONFIG_SHMEM
+ return get_mm_counter(mm, MM_SHMEMPAGES);
+#else
+ return 0;
+#endif
+}
+
static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
{
atomic_long_add(value, &mm->rss_stat.count[member]);
@@ -1379,9 +1389,27 @@ static inline void dec_mm_counter(struct mm_struct *mm, int member)
atomic_long_dec(&mm->rss_stat.count[member]);
}
+/* Optimized variant when page is already known not to be PageAnon */
+static inline int mm_counter_file(struct page *page)
+{
+#ifdef CONFIG_SHMEM
+ if (PageSwapBacked(page))
+ return MM_SHMEMPAGES;
+#endif
+ return MM_FILEPAGES;
+}
+
+static inline int mm_counter(struct page *page)
+{
+ if (PageAnon(page))
+ return MM_ANONPAGES;
+ return mm_counter_file(page);
+}
+
static inline unsigned long get_mm_rss(struct mm_struct *mm)
{
return get_mm_counter(mm, MM_FILEPAGES) +
+ get_mm_counter_shmem(mm) +
get_mm_counter(mm, MM_ANONPAGES);
}
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 199a03a..d3c2372 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -327,9 +327,12 @@ struct core_state {
};
enum {
- MM_FILEPAGES,
- MM_ANONPAGES,
- MM_SWAPENTS,
+ MM_FILEPAGES, /* Resident file mapping pages */
+ MM_ANONPAGES, /* Resident anonymous pages */
+ MM_SWAPENTS, /* Anonymous swap entries */
+#ifdef CONFIG_SHMEM
+ MM_SHMEMPAGES, /* Resident shared memory pages */
+#endif
NR_MM_COUNTERS
};
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index cb346f2..0a08fdd 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_counter(mm, mm_counter_file(page));
inc_mm_counter(mm, MM_ANONPAGES);
}
diff --git a/mm/memory.c b/mm/memory.c
index 411144f..db66400 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -832,10 +832,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
} else if (is_migration_entry(entry)) {
page = migration_entry_to_page(entry);
- if (PageAnon(page))
- rss[MM_ANONPAGES]++;
- else
- rss[MM_FILEPAGES]++;
+ rss[mm_counter(page)]++;
if (is_write_migration_entry(entry) &&
is_cow_mapping(vm_flags)) {
@@ -874,10 +871,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
if (page) {
get_page(page);
page_dup_rmap(page);
- if (PageAnon(page))
- rss[MM_ANONPAGES]++;
- else
- rss[MM_FILEPAGES]++;
+ rss[mm_counter(page)]++;
}
out_set_pte:
@@ -1113,9 +1107,8 @@ again:
tlb_remove_tlb_entry(tlb, pte, addr);
if (unlikely(!page))
continue;
- if (PageAnon(page))
- rss[MM_ANONPAGES]--;
- else {
+
+ if (!PageAnon(page)) {
if (pte_dirty(ptent)) {
force_flush = 1;
set_page_dirty(page);
@@ -1123,8 +1116,8 @@ again:
if (pte_young(ptent) &&
likely(!(vma->vm_flags & VM_SEQ_READ)))
mark_page_accessed(page);
- rss[MM_FILEPAGES]--;
}
+ rss[mm_counter(page)]--;
page_remove_rmap(page);
if (unlikely(page_mapcount(page) < 0))
print_bad_pte(vma, addr, ptent, page);
@@ -1146,11 +1139,7 @@ again:
struct page *page;
page = migration_entry_to_page(entry);
-
- if (PageAnon(page))
- rss[MM_ANONPAGES]--;
- else
- rss[MM_FILEPAGES]--;
+ rss[mm_counter(page)]--;
}
if (unlikely(!free_swap_and_cache(entry)))
print_bad_pte(vma, addr, ptent, NULL);
@@ -1460,7 +1449,7 @@ 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_counter_fast(mm, mm_counter_file(page));
page_add_file_rmap(page);
set_pte_at(mm, addr, pte, mk_pte(page, prot));
@@ -2174,7 +2163,8 @@ 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_counter_fast(mm,
+ mm_counter_file(old_page));
inc_mm_counter_fast(mm, MM_ANONPAGES);
}
} else
@@ -2703,7 +2693,7 @@ 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_counter_fast(vma->vm_mm, mm_counter_file(page));
page_add_file_rmap(page);
}
set_pte_at(vma->vm_mm, address, pte, entry);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 642f38c..a5ee3a2 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -573,10 +573,11 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
/* mm cannot safely be dereferenced after task_unlock(victim) */
mm = victim->mm;
mark_tsk_oom_victim(victim);
- pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
+ pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
K(get_mm_counter(victim->mm, MM_ANONPAGES)),
- K(get_mm_counter(victim->mm, MM_FILEPAGES)));
+ K(get_mm_counter(victim->mm, MM_FILEPAGES)),
+ K(get_mm_counter_shmem(victim->mm)));
task_unlock(victim);
/*
diff --git a/mm/rmap.c b/mm/rmap.c
index 5e3e090..e3c4392 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1216,12 +1216,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
update_hiwater_rss(mm);
if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
- if (!PageHuge(page)) {
- if (PageAnon(page))
- dec_mm_counter(mm, MM_ANONPAGES);
- else
- dec_mm_counter(mm, MM_FILEPAGES);
- }
+ if (!PageHuge(page))
+ dec_mm_counter(mm, mm_counter(page));
set_pte_at(mm, address, pte,
swp_entry_to_pte(make_hwpoison_entry(page)));
} else if (pte_unused(pteval)) {
@@ -1230,10 +1226,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
* interest anymore. Simply discard the pte, vmscan
* will take care of the rest.
*/
- if (PageAnon(page))
- dec_mm_counter(mm, MM_ANONPAGES);
- else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_counter(mm, mm_counter(page));
} else if (PageAnon(page)) {
swp_entry_t entry = { .val = page_private(page) };
pte_t swp_pte;
@@ -1276,7 +1269,7 @@ 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_counter(mm, mm_counter_file(page));
page_remove_rmap(page);
page_cache_release(page);
--
2.1.4
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