[PATCH] mm: rss = file_rss + anon_rss
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@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory.c b/mm/memory.c
index 51eb385..59d42e5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -397,9 +397,10 @@
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 @@
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 @@
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 @@
/* 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 @@
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 @@
*/
/* 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 @@
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;