[PATCH 1/2] mm: oom: add memcg to oom_control

From: Vladimir Davydov
Date: Fri May 27 2016 - 10:17:57 EST


It's a part of oom context just like allocation order and nodemask, so
let's move it to oom_control instead of passing it in the argument list.

Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
drivers/tty/sysrq.c | 1 +
include/linux/oom.h | 8 +++++---
mm/memcontrol.c | 5 +++--
mm/oom_kill.c | 32 +++++++++++++++-----------------
mm/page_alloc.c | 1 +
5 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index e5139402e7f8..52bbd27e93ae 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -363,6 +363,7 @@ static void moom_callback(struct work_struct *ignored)
struct oom_control oc = {
.zonelist = node_zonelist(first_memory_node, gfp_mask),
.nodemask = NULL,
+ .memcg = NULL,
.gfp_mask = gfp_mask,
.order = -1,
};
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 83469522690a..cbc24a5fe28d 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -23,6 +23,9 @@ struct oom_control {
/* Used to determine mempolicy */
nodemask_t *nodemask;

+ /* Memory cgroup in which oom is invoked, or NULL for global oom */
+ struct mem_cgroup *memcg;
+
/* Used to determine cpuset and node locality requirement */
const gfp_t gfp_mask;

@@ -83,11 +86,10 @@ extern unsigned long oom_badness(struct task_struct *p,

extern void oom_kill_process(struct oom_control *oc, struct task_struct *p,
unsigned int points, unsigned long totalpages,
- struct mem_cgroup *memcg, const char *message);
+ const char *message);

extern void check_panic_on_oom(struct oom_control *oc,
- enum oom_constraint constraint,
- struct mem_cgroup *memcg);
+ enum oom_constraint constraint);

extern enum oom_scan_t oom_scan_process_thread(struct oom_control *oc,
struct task_struct *task, unsigned long totalpages);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 37ba604984c9..eeb3b14de01a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1259,6 +1259,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
struct oom_control oc = {
.zonelist = NULL,
.nodemask = NULL,
+ .memcg = memcg,
.gfp_mask = gfp_mask,
.order = order,
};
@@ -1281,7 +1282,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
goto unlock;
}

- check_panic_on_oom(&oc, CONSTRAINT_MEMCG, memcg);
+ check_panic_on_oom(&oc, CONSTRAINT_MEMCG);
totalpages = mem_cgroup_get_limit(memcg) ? : 1;
for_each_mem_cgroup_tree(iter, memcg) {
struct css_task_iter it;
@@ -1329,7 +1330,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,

if (chosen) {
points = chosen_points * 1000 / totalpages;
- oom_kill_process(&oc, chosen, points, totalpages, memcg,
+ oom_kill_process(&oc, chosen, points, totalpages,
"Memory cgroup out of memory");
}
unlock:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index b95c4c101b35..b3424199069b 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -383,8 +383,7 @@ static void dump_tasks(struct mem_cgroup *memcg, const nodemask_t *nodemask)
rcu_read_unlock();
}

-static void dump_header(struct oom_control *oc, struct task_struct *p,
- struct mem_cgroup *memcg)
+static void dump_header(struct oom_control *oc, struct task_struct *p)
{
pr_warn("%s invoked oom-killer: gfp_mask=%#x(%pGg), order=%d, oom_score_adj=%hd\n",
current->comm, oc->gfp_mask, &oc->gfp_mask, oc->order,
@@ -392,12 +391,12 @@ static void dump_header(struct oom_control *oc, struct task_struct *p,

cpuset_print_current_mems_allowed();
dump_stack();
- if (memcg)
- mem_cgroup_print_oom_info(memcg, p);
+ if (oc->memcg)
+ mem_cgroup_print_oom_info(oc->memcg, p);
else
show_mem(SHOW_MEM_FILTER_NODES);
if (sysctl_oom_dump_tasks)
- dump_tasks(memcg, oc->nodemask);
+ dump_tasks(oc->memcg, oc->nodemask);
}

/*
@@ -748,7 +747,7 @@ void oom_killer_enable(void)
*/
void oom_kill_process(struct oom_control *oc, struct task_struct *p,
unsigned int points, unsigned long totalpages,
- struct mem_cgroup *memcg, const char *message)
+ const char *message)
{
struct task_struct *victim = p;
struct task_struct *child;
@@ -774,7 +773,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
task_unlock(p);

if (__ratelimit(&oom_rs))
- dump_header(oc, p, memcg);
+ dump_header(oc, p);

pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n",
message, task_pid_nr(p), p->comm, points);
@@ -795,8 +794,8 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
/*
* oom_badness() returns 0 if the thread is unkillable
*/
- child_points = oom_badness(child, memcg, oc->nodemask,
- totalpages);
+ child_points = oom_badness(child,
+ oc->memcg, oc->nodemask, totalpages);
if (child_points > victim_points) {
put_task_struct(victim);
victim = child;
@@ -874,8 +873,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
/*
* Determines whether the kernel must panic because of the panic_on_oom sysctl.
*/
-void check_panic_on_oom(struct oom_control *oc, enum oom_constraint constraint,
- struct mem_cgroup *memcg)
+void check_panic_on_oom(struct oom_control *oc, enum oom_constraint constraint)
{
if (likely(!sysctl_panic_on_oom))
return;
@@ -891,7 +889,7 @@ void check_panic_on_oom(struct oom_control *oc, enum oom_constraint constraint,
/* Do not panic for oom kills triggered by sysrq */
if (is_sysrq_oom(oc))
return;
- dump_header(oc, NULL, memcg);
+ dump_header(oc, NULL);
panic("Out of memory: %s panic_on_oom is enabled\n",
sysctl_panic_on_oom == 2 ? "compulsory" : "system-wide");
}
@@ -966,13 +964,13 @@ bool out_of_memory(struct oom_control *oc)
constraint = constrained_alloc(oc, &totalpages);
if (constraint != CONSTRAINT_MEMORY_POLICY)
oc->nodemask = NULL;
- check_panic_on_oom(oc, constraint, NULL);
+ check_panic_on_oom(oc, constraint);

if (sysctl_oom_kill_allocating_task && current->mm &&
!oom_unkillable_task(current, NULL, oc->nodemask) &&
current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
get_task_struct(current);
- oom_kill_process(oc, current, 0, totalpages, NULL,
+ oom_kill_process(oc, current, 0, totalpages,
"Out of memory (oom_kill_allocating_task)");
return true;
}
@@ -980,12 +978,11 @@ bool out_of_memory(struct oom_control *oc)
p = select_bad_process(oc, &points, totalpages);
/* Found nothing?!?! Either we hang forever, or we panic. */
if (!p && !is_sysrq_oom(oc)) {
- dump_header(oc, NULL, NULL);
+ dump_header(oc, NULL);
panic("Out of memory and no killable processes...\n");
}
if (p && p != (void *)-1UL) {
- oom_kill_process(oc, p, points, totalpages, NULL,
- "Out of memory");
+ oom_kill_process(oc, p, points, totalpages, "Out of memory");
/*
* Give the killed process a good chance to exit before trying
* to allocate memory again.
@@ -1005,6 +1002,7 @@ void pagefault_out_of_memory(void)
struct oom_control oc = {
.zonelist = NULL,
.nodemask = NULL,
+ .memcg = NULL,
.gfp_mask = 0,
.order = 0,
};
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f21f56f88c8a..7da8310b86e9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3101,6 +3101,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
struct oom_control oc = {
.zonelist = ac->zonelist,
.nodemask = ac->nodemask,
+ .memcg = NULL,
.gfp_mask = gfp_mask,
.order = order,
};
--
2.1.4