Commit 626ebc41 authored by Tejun Heo's avatar Tejun Heo Committed by Linus Torvalds
Browse files

memcg: flatten task_struct->memcg_oom 



task_struct->memcg_oom is a sub-struct containing fields which are used
for async memcg oom handling.  Most task_struct fields aren't packaged
this way and it can lead to unnecessary alignment paddings.  This patch
flattens it.

* task.memcg_oom.memcg          -> task.memcg_in_oom
* task.memcg_oom.gfp_mask	-> task.memcg_oom_gfp_mask
* task.memcg_oom.order          -> task.memcg_oom_order
* task.memcg_oom.may_oom        -> task.memcg_may_oom

In addition, task.memcg_may_oom is relocated to where other bitfields are
which reduces the size of task_struct.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarVladimir Davydov <vdavydov@parallels.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 55e1ceaf

include/linux/memcontrol.h

+5 −5
Original line number Diff line number Diff line
@@ -406,19 +406,19 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, 


static inline void mem_cgroup_oom_enable(void)

{

	WARN_ON(current->memcg_oom.may_oom);

	current->memcg_oom.may_oom = 1;

	WARN_ON(current->memcg_may_oom);

	current->memcg_may_oom = 1;

}



static inline void mem_cgroup_oom_disable(void)

{

	WARN_ON(!current->memcg_oom.may_oom);

	current->memcg_oom.may_oom = 0;

	WARN_ON(!current->memcg_may_oom);

	current->memcg_may_oom = 0;

}



static inline bool task_in_memcg_oom(struct task_struct *p)

{

	return p->memcg_oom.memcg;

	return p->memcg_in_oom;

}



bool mem_cgroup_oom_synchronize(bool wait);

include/linux/sched.h

+6 −7
Original line number Diff line number Diff line
@@ -1473,7 +1473,9 @@ struct task_struct { 
	unsigned sched_reset_on_fork:1;

	unsigned sched_contributes_to_load:1;

	unsigned sched_migrated:1;



#ifdef CONFIG_MEMCG

	unsigned memcg_may_oom:1;

#endif

#ifdef CONFIG_MEMCG_KMEM

	unsigned memcg_kmem_skip_account:1;

#endif
@@ -1804,12 +1806,9 @@ struct task_struct { 
	unsigned long trace_recursion;

#endif /* CONFIG_TRACING */

#ifdef CONFIG_MEMCG

	struct memcg_oom_info {

		struct mem_cgroup *memcg;

		gfp_t gfp_mask;

		int order;

		unsigned int may_oom:1;

	} memcg_oom;

	struct mem_cgroup *memcg_in_oom;

	gfp_t memcg_oom_gfp_mask;

	int memcg_oom_order;

#endif

#ifdef CONFIG_UPROBES

	struct uprobe_task *utask;

mm/memcontrol.c

+8 −8
Original line number Diff line number Diff line
@@ -1661,7 +1661,7 @@ static void memcg_oom_recover(struct mem_cgroup *memcg) 


static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)

{

	if (!current->memcg_oom.may_oom)

	if (!current->memcg_may_oom)

		return;

	/*

	 * We are in the middle of the charge context here, so we
@@ -1678,9 +1678,9 @@ static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) 
	 * and when we know whether the fault was overall successful.

	 */

	css_get(&memcg->css);

	current->memcg_oom.memcg = memcg;

	current->memcg_oom.gfp_mask = mask;

	current->memcg_oom.order = order;

	current->memcg_in_oom = memcg;

	current->memcg_oom_gfp_mask = mask;

	current->memcg_oom_order = order;

}



/**
@@ -1702,7 +1702,7 @@ static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) 
 */

bool mem_cgroup_oom_synchronize(bool handle)

{

	struct mem_cgroup *memcg = current->memcg_oom.memcg;

	struct mem_cgroup *memcg = current->memcg_in_oom;

	struct oom_wait_info owait;

	bool locked;
@@ -1730,8 +1730,8 @@ bool mem_cgroup_oom_synchronize(bool handle) 
	if (locked && !memcg->oom_kill_disable) {

		mem_cgroup_unmark_under_oom(memcg);

		finish_wait(&memcg_oom_waitq, &owait.wait);

		mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask,

					 current->memcg_oom.order);

		mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask,

					 current->memcg_oom_order);

	} else {

		schedule();

		mem_cgroup_unmark_under_oom(memcg);
@@ -1748,7 +1748,7 @@ bool mem_cgroup_oom_synchronize(bool handle) 
		memcg_oom_recover(memcg);

	}

cleanup:

	current->memcg_oom.memcg = NULL;

	current->memcg_in_oom = NULL;

	css_put(&memcg->css);

	return true;

}

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