[PATCH 16/21] mm: rss = file_rss + anon_rss

From: Hugh Dickins
Date: Sun Sep 25 2005 - 11:08:01 EST


I was lazy when we added anon_rss, and chose to change as few places as
possible. So currently each anonymous page has to be counted twice, in
rss and in anon_rss. Which won't be so good if those are atomic counts
in some configurations.

Change that around: keep file_rss and anon_rss separately, and add them
together (with get_mm_rss macro) when the total is needed - reading two
atomics is much cheaper than updating two atomics. And update anon_rss
upfront, typically in memory.c, not tucked away in page_add_anon_rmap.

Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
---

fs/exec.c | 2 +-
fs/proc/array.c | 2 +-
fs/proc/task_mmu.c | 8 +++-----
include/linux/sched.h | 4 +++-
kernel/acct.c | 2 +-
kernel/fork.c | 4 ++--
mm/fremap.c | 4 ++--
mm/hugetlb.c | 6 +++---
mm/memory.c | 31 +++++++++++++++++--------------
mm/nommu.c | 2 +-
mm/rmap.c | 8 +++-----
mm/swapfile.c | 2 +-
12 files changed, 38 insertions(+), 37 deletions(-)

--- mm15/fs/exec.c 2005-09-22 12:31:59.000000000 +0100
+++ mm16/fs/exec.c 2005-09-24 19:29:53.000000000 +0100
@@ -330,7 +330,7 @@ void install_arg_page(struct vm_area_str
pte_unmap(pte);
goto out;
}
- inc_mm_counter(mm, rss);
+ inc_mm_counter(mm, anon_rss);
lru_cache_add_active(page);
set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte(
page, vma->vm_page_prot))));
--- mm15/fs/proc/array.c 2005-09-21 12:16:44.000000000 +0100
+++ mm16/fs/proc/array.c 2005-09-24 19:29:53.000000000 +0100
@@ -438,7 +438,7 @@ static int do_task_stat(struct task_stru
jiffies_to_clock_t(it_real_value),
start_time,
vsize,
- mm ? get_mm_counter(mm, rss) : 0, /* you might want to shift this left 3 */
+ mm ? get_mm_rss(mm) : 0,
rsslim,
mm ? mm->start_code : 0,
mm ? mm->end_code : 0,
--- mm15/fs/proc/task_mmu.c 2005-09-22 12:32:00.000000000 +0100
+++ mm16/fs/proc/task_mmu.c 2005-09-24 19:29:53.000000000 +0100
@@ -29,7 +29,7 @@ char *task_mem(struct mm_struct *mm, cha
"VmPTE:\t%8lu kB\n",
(mm->total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
mm->locked_vm << (PAGE_SHIFT-10),
- get_mm_counter(mm, rss) << (PAGE_SHIFT-10),
+ get_mm_rss(mm) << (PAGE_SHIFT-10),
data << (PAGE_SHIFT-10),
mm->stack_vm << (PAGE_SHIFT-10), text, lib,
(PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10);
@@ -44,13 +44,11 @@ unsigned long task_vsize(struct mm_struc
int task_statm(struct mm_struct *mm, int *shared, int *text,
int *data, int *resident)
{
- int rss = get_mm_counter(mm, rss);
-
- *shared = rss - get_mm_counter(mm, anon_rss);
+ *shared = get_mm_counter(mm, file_rss);
*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
>> PAGE_SHIFT;
*data = mm->total_vm - mm->shared_vm;
- *resident = rss;
+ *resident = *shared + get_mm_counter(mm, anon_rss);
return mm->total_vm;
}

--- mm15/include/linux/sched.h 2005-09-22 12:32:03.000000000 +0100
+++ mm16/include/linux/sched.h 2005-09-24 19:29:53.000000000 +0100
@@ -243,6 +243,8 @@ extern void arch_unmap_area_topdown(stru
#define add_mm_counter(mm, member, value) (mm)->_##member += (value)
#define inc_mm_counter(mm, member) (mm)->_##member++
#define dec_mm_counter(mm, member) (mm)->_##member--
+#define get_mm_rss(mm) ((mm)->_file_rss + (mm)->_anon_rss)
+
typedef unsigned long mm_counter_t;

struct mm_struct {
@@ -275,7 +277,7 @@ struct mm_struct {
unsigned long exec_vm, stack_vm, reserved_vm, def_flags, nr_ptes;

/* Special counters protected by the page_table_lock */
- mm_counter_t _rss;
+ mm_counter_t _file_rss;
mm_counter_t _anon_rss;

unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
--- mm15/kernel/acct.c 2005-09-21 12:16:59.000000000 +0100
+++ mm16/kernel/acct.c 2005-09-24 19:29:53.000000000 +0100
@@ -553,7 +553,7 @@ void acct_update_integrals(struct task_s
if (delta == 0)
return;
tsk->acct_stimexpd = tsk->stime;
- tsk->acct_rss_mem1 += delta * get_mm_counter(tsk->mm, rss);
+ tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm);
tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
}
}
--- mm15/kernel/fork.c 2005-09-24 19:29:40.000000000 +0100
+++ mm16/kernel/fork.c 2005-09-24 19:29:53.000000000 +0100
@@ -321,7 +321,7 @@ static struct mm_struct * mm_init(struct
INIT_LIST_HEAD(&mm->mmlist);
mm->core_waiters = 0;
mm->nr_ptes = 0;
- set_mm_counter(mm, rss, 0);
+ set_mm_counter(mm, file_rss, 0);
set_mm_counter(mm, anon_rss, 0);
spin_lock_init(&mm->page_table_lock);
rwlock_init(&mm->ioctx_list_lock);
@@ -499,7 +499,7 @@ static int copy_mm(unsigned long clone_f
if (retval)
goto free_pt;

- mm->hiwater_rss = get_mm_counter(mm,rss);
+ mm->hiwater_rss = get_mm_rss(mm);
mm->hiwater_vm = mm->total_vm;

good_mm:
--- mm15/mm/fremap.c 2005-06-17 20:48:29.000000000 +0100
+++ mm16/mm/fremap.c 2005-09-24 19:29:53.000000000 +0100
@@ -39,7 +39,7 @@ static inline void zap_pte(struct mm_str
set_page_dirty(page);
page_remove_rmap(page);
page_cache_release(page);
- dec_mm_counter(mm, rss);
+ dec_mm_counter(mm, file_rss);
}
}
} else {
@@ -92,7 +92,7 @@ int install_page(struct mm_struct *mm, s

zap_pte(mm, vma, addr, pte);

- inc_mm_counter(mm,rss);
+ inc_mm_counter(mm, file_rss);
flush_icache_page(vma, page);
set_pte_at(mm, addr, pte, mk_pte(page, prot));
page_add_file_rmap(page);
--- mm15/mm/hugetlb.c 2005-09-24 19:26:24.000000000 +0100
+++ mm16/mm/hugetlb.c 2005-09-24 19:29:53.000000000 +0100
@@ -285,7 +285,7 @@ int copy_hugetlb_page_range(struct mm_st
entry = *src_pte;
ptepage = pte_page(entry);
get_page(ptepage);
- add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
+ add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE);
set_huge_pte_at(dst, addr, dst_pte, entry);
}
spin_unlock(&src->page_table_lock);
@@ -323,7 +323,7 @@ void unmap_hugepage_range(struct vm_area

page = pte_page(pte);
put_page(page);
- add_mm_counter(mm, rss, - (HPAGE_SIZE / PAGE_SIZE));
+ add_mm_counter(mm, file_rss, - (HPAGE_SIZE / PAGE_SIZE));
}
flush_tlb_range(vma, start, end);
}
@@ -385,7 +385,7 @@ int hugetlb_prefault(struct address_spac
goto out;
}
}
- add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
+ add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE);
set_huge_pte_at(mm, addr, pte, make_huge_pte(vma, page));
}
out:
--- mm15/mm/memory.c 2005-09-24 19:29:25.000000000 +0100
+++ mm16/mm/memory.c 2005-09-24 19:29:53.000000000 +0100
@@ -397,9 +397,10 @@ copy_one_pte(struct mm_struct *dst_mm, s
pte = pte_mkclean(pte);
pte = pte_mkold(pte);
get_page(page);
- inc_mm_counter(dst_mm, rss);
if (PageAnon(page))
inc_mm_counter(dst_mm, anon_rss);
+ else
+ inc_mm_counter(dst_mm, file_rss);
set_pte_at(dst_mm, addr, dst_pte, pte);
page_dup_rmap(page);
}
@@ -581,8 +582,8 @@ static void zap_pte_range(struct mmu_gat
set_page_dirty(page);
if (pte_young(ptent))
mark_page_accessed(page);
+ dec_mm_counter(tlb->mm, file_rss);
}
- dec_mm_counter(tlb->mm, rss);
page_remove_rmap(page);
tlb_remove_page(tlb, page);
continue;
@@ -1290,13 +1291,15 @@ static int do_wp_page(struct mm_struct *
spin_lock(&mm->page_table_lock);
page_table = pte_offset_map(pmd, address);
if (likely(pte_same(*page_table, orig_pte))) {
- if (PageAnon(old_page))
- dec_mm_counter(mm, anon_rss);
if (PageReserved(old_page))
- inc_mm_counter(mm, rss);
- else
+ inc_mm_counter(mm, anon_rss);
+ else {
page_remove_rmap(old_page);
-
+ if (!PageAnon(old_page)) {
+ inc_mm_counter(mm, anon_rss);
+ dec_mm_counter(mm, file_rss);
+ }
+ }
flush_cache_page(vma, address, pfn);
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
@@ -1701,7 +1704,7 @@ static int do_swap_page(struct mm_struct

/* The page isn't present yet, go ahead with the fault. */

- inc_mm_counter(mm, rss);
+ inc_mm_counter(mm, anon_rss);
pte = mk_pte(page, vma->vm_page_prot);
if (write_access && can_share_swap_page(page)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
@@ -1774,7 +1777,7 @@ static int do_anonymous_page(struct mm_s
page_cache_release(page);
goto unlock;
}
- inc_mm_counter(mm, rss);
+ inc_mm_counter(mm, anon_rss);
entry = mk_pte(page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
lru_cache_add_active(page);
@@ -1887,19 +1890,19 @@ retry:
*/
/* Only go through if we didn't race with anybody else... */
if (pte_none(*page_table)) {
- if (!PageReserved(new_page))
- inc_mm_counter(mm, rss);
-
flush_icache_page(vma, new_page);
entry = mk_pte(new_page, vma->vm_page_prot);
if (write_access)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
set_pte_at(mm, address, page_table, entry);
if (anon) {
+ inc_mm_counter(mm, anon_rss);
lru_cache_add_active(new_page);
page_add_anon_rmap(new_page, vma, address);
- } else
+ } else if (!PageReserved(new_page)) {
+ inc_mm_counter(mm, file_rss);
page_add_file_rmap(new_page);
+ }
} else {
/* One of our sibling threads was faster, back out. */
page_cache_release(new_page);
@@ -2192,7 +2195,7 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
void update_mem_hiwater(struct task_struct *tsk)
{
if (tsk->mm) {
- unsigned long rss = get_mm_counter(tsk->mm, rss);
+ unsigned long rss = get_mm_rss(tsk->mm);

if (tsk->mm->hiwater_rss < rss)
tsk->mm->hiwater_rss = rss;
--- mm15/mm/nommu.c 2005-09-22 12:32:03.000000000 +0100
+++ mm16/mm/nommu.c 2005-09-24 19:29:53.000000000 +0100
@@ -1080,7 +1080,7 @@ void update_mem_hiwater(struct task_stru
unsigned long rss;

if (likely(tsk->mm)) {
- rss = get_mm_counter(tsk->mm, rss);
+ rss = get_mm_rss(tsk->mm);
if (tsk->mm->hiwater_rss < rss)
tsk->mm->hiwater_rss = rss;
if (tsk->mm->hiwater_vm < tsk->mm->total_vm)
--- mm15/mm/rmap.c 2005-09-22 12:32:04.000000000 +0100
+++ mm16/mm/rmap.c 2005-09-24 19:29:53.000000000 +0100
@@ -445,8 +445,6 @@ void page_add_anon_rmap(struct page *pag
{
BUG_ON(PageReserved(page));

- inc_mm_counter(vma->vm_mm, anon_rss);
-
if (atomic_inc_and_test(&page->_mapcount)) {
struct anon_vma *anon_vma = vma->anon_vma;

@@ -561,9 +559,9 @@ static int try_to_unmap_one(struct page
set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
BUG_ON(pte_file(*pte));
dec_mm_counter(mm, anon_rss);
- }
+ } else
+ dec_mm_counter(mm, file_rss);

- dec_mm_counter(mm, rss);
page_remove_rmap(page);
page_cache_release(page);

@@ -667,7 +665,7 @@ static void try_to_unmap_cluster(unsigne

page_remove_rmap(page);
page_cache_release(page);
- dec_mm_counter(mm, rss);
+ dec_mm_counter(mm, file_rss);
(*mapcount)--;
}

--- mm15/mm/swapfile.c 2005-09-24 19:27:19.000000000 +0100
+++ mm16/mm/swapfile.c 2005-09-24 19:29:53.000000000 +0100
@@ -405,7 +405,7 @@ void free_swap_and_cache(swp_entry_t ent
static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
unsigned long addr, swp_entry_t entry, struct page *page)
{
- inc_mm_counter(vma->vm_mm, rss);
+ inc_mm_counter(vma->vm_mm, anon_rss);
get_page(page);
set_pte_at(vma->vm_mm, addr, pte,
pte_mkold(mk_pte(page, vma->vm_page_prot)));
-
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