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memcg: oom wakeup filter 

memcg's oom waitqueue is a system-wide wait_queue (for handling
hierarchy.) So, it's better to add custom wake function and do filtering
in wake up path.

This patch adds a filtering feature for waking up oom-waiters.  Hierarchy
is properly handled.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
KAMEZAWA Hiroyuki 2010-05-26 14:42:36 -07:00 committed by Linus Torvalds
parent 595f4b694c
commit dc98df5a1b
1 changed files with 46 additions and 17 deletions
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63
mm/memcontrol.c
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@ -1293,14 +1293,56 @@ static void mem_cgroup_oom_unlock(struct mem_cgroup *mem)
static DEFINE_MUTEX(memcg_oom_mutex);
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
struct oom_wait_info {
struct mem_cgroup *mem;
wait_queue_t wait;
};
static int memcg_oom_wake_function(wait_queue_t *wait,
unsigned mode, int sync, void *arg)
{
struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
struct oom_wait_info *oom_wait_info;
oom_wait_info = container_of(wait, struct oom_wait_info, wait);
if (oom_wait_info->mem == wake_mem)
goto wakeup;
/* if no hierarchy, no match */
if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
return 0;
/*
* Both of oom_wait_info->mem and wake_mem are stable under us.
* Then we can use css_is_ancestor without taking care of RCU.
*/
if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
!css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
return 0;
wakeup:
return autoremove_wake_function(wait, mode, sync, arg);
}
static void memcg_wakeup_oom(struct mem_cgroup *mem)
{
/* for filtering, pass "mem" as argument. */
__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
}
/*
* try to call OOM killer. returns false if we should exit memory-reclaim loop.
*/
bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
{
DEFINE_WAIT(wait);
struct oom_wait_info owait;
bool locked;
owait.mem = mem;
owait.wait.flags = 0;
owait.wait.func = memcg_oom_wake_function;
owait.wait.private = current;
INIT_LIST_HEAD(&owait.wait.task_list);
/* At first, try to OOM lock hierarchy under mem.*/
mutex_lock(&memcg_oom_mutex);
locked = mem_cgroup_oom_lock(mem);
@ -1310,31 +1352,18 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
* under OOM is always welcomed, use TASK_KILLABLE here.
*/
if (!locked)
prepare_to_wait(&memcg_oom_waitq, &wait, TASK_KILLABLE);
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
mutex_unlock(&memcg_oom_mutex);
if (locked)
mem_cgroup_out_of_memory(mem, mask);
else {
schedule();
finish_wait(&memcg_oom_waitq, &wait);
finish_wait(&memcg_oom_waitq, &owait.wait);
}
mutex_lock(&memcg_oom_mutex);
mem_cgroup_oom_unlock(mem);
/*
* Here, we use global waitq .....more fine grained waitq ?
* Assume following hierarchy.
* A/
* 01
* 02
* assume OOM happens both in A and 01 at the same time. Tthey are
* mutually exclusive by lock. (kill in 01 helps A.)
* When we use per memcg waitq, we have to wake up waiters on A and 02
* in addtion to waiters on 01. We use global waitq for avoiding mess.
* It will not be a big problem.
* (And a task may be moved to other groups while it's waiting for OOM.)
*/
wake_up_all(&memcg_oom_waitq);
memcg_wakeup_oom(mem);
mutex_unlock(&memcg_oom_mutex);
if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))