mm, shmem: add internal shmem resident memory accounting
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.
The internal accounting currently counts shmem pages together with
regular files. As a preparation to extend the userspace interfaces,
this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for
shmem pages separately from MM_FILEPAGES. The next patch will expose it
to userspace - this patch doesn't change the exported values yet, by
adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was
used before. The only user-visible change after this patch is the OOM
killer message that separates the reported "shmem-rss" from "file-rss".
[vbabka@suse.cz: forward-porting, tweak changelog]
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-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/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 63b03989..aa34af0 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -603,10 +603,7 @@
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 8a03759..45eb241 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -83,7 +83,8 @@
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 00bad77..a8ab1fc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1361,10 +1361,26 @@
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)
+{
+ if (PageSwapBacked(page))
+ return MM_SHMEMPAGES;
+ 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(mm, MM_ANONPAGES);
+ get_mm_counter(mm, MM_ANONPAGES) +
+ get_mm_counter(mm, MM_SHMEMPAGES);
}
static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index f8d1492..207890b 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -369,9 +369,10 @@
};
enum {
- MM_FILEPAGES,
- MM_ANONPAGES,
- MM_SWAPENTS,
+ MM_FILEPAGES, /* Resident file mapping pages */
+ 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 7dad849..bb06691 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -180,7 +180,7 @@
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 c387430..f7026c0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -832,10 +832,7 @@
} 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 @@
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 @@
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 @@
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 @@
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 @@
/* 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));
@@ -2097,7 +2086,8 @@
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 {
@@ -2820,7 +2810,7 @@
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 c126809..dc490c0 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -585,10 +585,11 @@
*/
do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, true);
mark_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(victim->mm, MM_SHMEMPAGES)));
task_unlock(victim);
/*
diff --git a/mm/rmap.c b/mm/rmap.c
index 3c3f1d2..622756c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1364,10 +1364,7 @@
if (PageHuge(page)) {
hugetlb_count_sub(1 << compound_order(page), mm);
} else {
- if (PageAnon(page))
- dec_mm_counter(mm, MM_ANONPAGES);
- else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_counter(mm, mm_counter(page));
}
set_pte_at(mm, address, pte,
swp_entry_to_pte(make_hwpoison_entry(page)));
@@ -1377,10 +1374,7 @@
* 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 (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION)) {
swp_entry_t entry;
pte_t swp_pte;
@@ -1420,7 +1414,7 @@
swp_pte = pte_swp_mksoft_dirty(swp_pte);
set_pte_at(mm, address, pte, swp_pte);
} else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_counter(mm, mm_counter_file(page));
page_remove_rmap(page);
page_cache_release(page);