[PATCH] mm: fix rss and mmlist locking

A couple of oddities were guarded by page_table_lock, no longer properly
guarded when that is split.

The mm_counters of file_rss and anon_rss: make those an atomic_t, or an
atomic64_t if the architecture supports it, in such a case.  Definitions by
courtesy of Christoph Lameter: who spent considerable effort on more scalable
ways of counting, but found insufficient benefit in practice.

And adding an mm with swap to the mmlist for swapoff: the list is well-
guarded by its own lock, but the list_empty check now has to be repeated
inside it.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hugh Dickins 2005-10-29 18:16:41 -07:00 committed by Linus Torvalds
parent 4c21e2f244
commit f412ac08c9
3 changed files with 43 additions and 6 deletions

View file

@ -559,7 +559,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
swap_duplicate(entry);
if (list_empty(&mm->mmlist)) {
spin_lock(&mmlist_lock);
list_add(&mm->mmlist, &init_mm.mmlist);
if (list_empty(&mm->mmlist))
list_add(&mm->mmlist, &init_mm.mmlist);
spin_unlock(&mmlist_lock);
}
set_pte_at(mm, address, pte, swp_entry_to_pte(entry));