mm: memcontrol: remove explicit OOM parameter in charge path
For the page allocator, __GFP_NORETRY implies that no OOM should be
triggered, whereas memcg has an explicit parameter to disable OOM.
The only callsites that want OOM disabled are THP charges and charge
moving. THP already uses __GFP_NORETRY and charge moving can use it as
well - one full reclaim cycle should be plenty. Switch it over, then
remove the OOM parameter.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3069d64..8aaca82 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2555,15 +2555,13 @@
* mem_cgroup_try_charge - try charging a memcg
* @memcg: memcg to charge
* @nr_pages: number of pages to charge
- * @oom: trigger OOM if reclaim fails
*
* Returns 0 if @memcg was charged successfully, -EINTR if the charge
* was bypassed to root_mem_cgroup, and -ENOMEM if the charge failed.
*/
static int mem_cgroup_try_charge(struct mem_cgroup *memcg,
gfp_t gfp_mask,
- unsigned int nr_pages,
- bool oom)
+ unsigned int nr_pages)
{
unsigned int batch = max(CHARGE_BATCH, nr_pages);
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
@@ -2647,9 +2645,6 @@
if (fatal_signal_pending(current))
goto bypass;
- if (!oom)
- goto nomem;
-
mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(batch));
nomem:
if (!(gfp_mask & __GFP_NOFAIL))
@@ -2675,15 +2670,14 @@
*/
static struct mem_cgroup *mem_cgroup_try_charge_mm(struct mm_struct *mm,
gfp_t gfp_mask,
- unsigned int nr_pages,
- bool oom)
+ unsigned int nr_pages)
{
struct mem_cgroup *memcg;
int ret;
memcg = get_mem_cgroup_from_mm(mm);
- ret = mem_cgroup_try_charge(memcg, gfp_mask, nr_pages, oom);
+ ret = mem_cgroup_try_charge(memcg, gfp_mask, nr_pages);
css_put(&memcg->css);
if (ret == -EINTR)
memcg = root_mem_cgroup;
@@ -2900,8 +2894,7 @@
if (ret)
return ret;
- ret = mem_cgroup_try_charge(memcg, gfp, size >> PAGE_SHIFT,
- oom_gfp_allowed(gfp));
+ ret = mem_cgroup_try_charge(memcg, gfp, size >> PAGE_SHIFT);
if (ret == -EINTR) {
/*
* mem_cgroup_try_charge() chosed to bypass to root due to
@@ -3650,7 +3643,6 @@
{
unsigned int nr_pages = 1;
struct mem_cgroup *memcg;
- bool oom = true;
if (mem_cgroup_disabled())
return 0;
@@ -3662,14 +3654,9 @@
if (PageTransHuge(page)) {
nr_pages <<= compound_order(page);
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
- /*
- * Never OOM-kill a process for a huge page. The
- * fault handler will fall back to regular pages.
- */
- oom = false;
}
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, nr_pages, oom);
+ memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, nr_pages);
if (!memcg)
return -ENOMEM;
__mem_cgroup_commit_charge(memcg, page, nr_pages,
@@ -3706,7 +3693,7 @@
memcg = try_get_mem_cgroup_from_page(page);
if (!memcg)
memcg = get_mem_cgroup_from_mm(mm);
- ret = mem_cgroup_try_charge(memcg, mask, 1, true);
+ ret = mem_cgroup_try_charge(memcg, mask, 1);
css_put(&memcg->css);
if (ret == -EINTR)
memcg = root_mem_cgroup;
@@ -3733,7 +3720,7 @@
if (!PageSwapCache(page)) {
struct mem_cgroup *memcg;
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1, true);
+ memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1);
if (!memcg)
return -ENOMEM;
*memcgp = memcg;
@@ -3802,7 +3789,7 @@
return 0;
}
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1, true);
+ memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1);
if (!memcg)
return -ENOMEM;
__mem_cgroup_commit_charge(memcg, page, 1, type, false);
@@ -6440,7 +6427,8 @@
batch_count = PRECHARGE_COUNT_AT_ONCE;
cond_resched();
}
- ret = mem_cgroup_try_charge(memcg, GFP_KERNEL, 1, false);
+ ret = mem_cgroup_try_charge(memcg,
+ GFP_KERNEL & ~__GFP_NORETRY, 1);
if (ret)
/* mem_cgroup_clear_mc() will do uncharge later */
return ret;