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authorHugh Dickins <hugh@veritas.com>2008-02-07 00:14:19 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:20 -0800
commit3be91277e754c7db04eae145ba622b3a3e3ad96d (patch)
tree347aa7cd186ed87ba7585d63e6584c94fffc2fd6
parentac44d354d5c9ced49b1165d6496f134501134219 (diff)
memcgroup: tidy up mem_cgroup_charge_common
Tidy up mem_cgroup_charge_common before extending it. Adjust some comments, but mainly clean up its loop: I've an aversion to loops full of continues, then a break or a goto at the bottom. And the is_atomic test should be on the __GFP_WAIT bit, not GFP_ATOMIC bits. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memcontrol.c44
1 files changed, 15 insertions, 29 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 160101a05b4d..dbf571547c03 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -345,23 +345,22 @@ retry:
goto done;
}
}
-
unlock_page_cgroup(page);
pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
if (pc == NULL)
goto err;
- rcu_read_lock();
/*
- * We always charge the cgroup the mm_struct belongs to
- * the mm_struct's mem_cgroup changes on task migration if the
+ * We always charge the cgroup the mm_struct belongs to.
+ * The mm_struct's mem_cgroup changes on task migration if the
* thread group leader migrates. It's possible that mm is not
* set, if so charge the init_mm (happens for pagecache usage).
*/
if (!mm)
mm = &init_mm;
+ rcu_read_lock();
mem = rcu_dereference(mm->mem_cgroup);
/*
* For every charge from the cgroup, increment reference
@@ -375,12 +374,8 @@ retry:
* the cgroup limit.
*/
while (res_counter_charge(&mem->res, PAGE_SIZE)) {
- bool is_atomic = gfp_mask & GFP_ATOMIC;
- /*
- * We cannot reclaim under GFP_ATOMIC, fail the charge
- */
- if (is_atomic)
- goto noreclaim;
+ if (!(gfp_mask & __GFP_WAIT))
+ goto out;
if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
continue;
@@ -394,23 +389,12 @@ retry:
*/
if (res_counter_check_under_limit(&mem->res))
continue;
- /*
- * Since we control both RSS and cache, we end up with a
- * very interesting scenario where we end up reclaiming
- * memory (essentially RSS), since the memory is pushed
- * to swap cache, we eventually end up adding those
- * pages back to our list. Hence we give ourselves a
- * few chances before we fail
- */
- else if (nr_retries--) {
- congestion_wait(WRITE, HZ/10);
- continue;
+
+ if (!nr_retries--) {
+ mem_cgroup_out_of_memory(mem, gfp_mask);
+ goto out;
}
-noreclaim:
- css_put(&mem->css);
- if (!is_atomic)
- mem_cgroup_out_of_memory(mem, GFP_KERNEL);
- goto free_pc;
+ congestion_wait(WRITE, HZ/10);
}
atomic_set(&pc->ref_cnt, 1);
@@ -419,10 +403,11 @@ noreclaim:
pc->flags = 0;
if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
pc->flags |= PAGE_CGROUP_FLAG_CACHE;
+
if (page_cgroup_assign_new_page_cgroup(page, pc)) {
/*
- * an another charge is added to this page already.
- * we do take lock_page_cgroup(page) again and read
+ * Another charge has been added to this page already.
+ * We take lock_page_cgroup(page) again and read
* page->cgroup, increment refcnt.... just retry is OK.
*/
res_counter_uncharge(&mem->res, PAGE_SIZE);
@@ -437,7 +422,8 @@ noreclaim:
done:
return 0;
-free_pc:
+out:
+ css_put(&mem->css);
kfree(pc);
err:
return -ENOMEM;