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Commit 90254a65 authored by Daisuke Nishimura's avatar Daisuke Nishimura Committed by Linus Torvalds
Browse files

memcg: clean up move charge 



This patch cleans up move charge code by:

- define functions to handle pte for each types, and make
  is_target_pte_for_mc() cleaner.

- instead of checking the MOVE_CHARGE_TYPE_ANON bit, define a function
  that checks the bit.

Signed-off-by: default avatarDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3c11ecf4

mm/memcontrol.c

+59 −37
Original line number Diff line number Diff line
@@ -266,6 +266,12 @@ static struct move_charge_struct { 
	.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),

};



static bool move_anon(void)

{

	return test_bit(MOVE_CHARGE_TYPE_ANON,

					&mc.to->move_charge_at_immigrate);

}



/*

 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft

 * limit reclaim to prevent infinite loops, if they ever occur.
@@ -4162,50 +4168,66 @@ enum mc_target_type { 
	MC_TARGET_SWAP,

};



static int is_target_pte_for_mc(struct vm_area_struct *vma,

		unsigned long addr, pte_t ptent, union mc_target *target)

static struct page *mc_handle_present_pte(struct vm_area_struct *vma,

						unsigned long addr, pte_t ptent)

{

	struct page *page = NULL;

	struct page_cgroup *pc;

	int ret = 0;

	swp_entry_t ent = { .val = 0 };

	int usage_count = 0;

	bool move_anon = test_bit(MOVE_CHARGE_TYPE_ANON,

					&mc.to->move_charge_at_immigrate);

	struct page *page = vm_normal_page(vma, addr, ptent);



	if (!pte_present(ptent)) {

		/* TODO: handle swap of shmes/tmpfs */

		if (pte_none(ptent) || pte_file(ptent))

			return 0;

		else if (is_swap_pte(ptent)) {

			ent = pte_to_swp_entry(ptent);

			if (!move_anon || non_swap_entry(ent))

				return 0;

			usage_count = mem_cgroup_count_swap_user(ent, &page);

		}

	} else {

		page = vm_normal_page(vma, addr, ptent);

	if (!page || !page_mapped(page))

			return 0;

		return NULL;

	if (PageAnon(page)) {

		/* we don't move shared anon */

		if (!move_anon() || page_mapcount(page) > 2)

			return NULL;

	} else

		/*

		 * TODO: We don't move charges of file(including shmem/tmpfs)

		 * pages for now.

		 */

		if (!move_anon || !PageAnon(page))

			return 0;

		return NULL;

	if (!get_page_unless_zero(page))

			return 0;

		usage_count = page_mapcount(page);

		return NULL;



	return page;

}

	if (usage_count > 1) {

		/*

		 * TODO: We don't move charges of shared(used by multiple

		 * processes) pages for now.

		 */



static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,

			unsigned long addr, pte_t ptent, swp_entry_t *entry)

{

	int usage_count;

	struct page *page = NULL;

	swp_entry_t ent = pte_to_swp_entry(ptent);



	if (!move_anon() || non_swap_entry(ent))

		return NULL;

	usage_count = mem_cgroup_count_swap_user(ent, &page);

	if (usage_count > 1) { /* we don't move shared anon */

		if (page)

			put_page(page);

		return 0;

		return NULL;

	}

	if (do_swap_account)

		entry->val = ent.val;



	return page;

}



static int is_target_pte_for_mc(struct vm_area_struct *vma,

		unsigned long addr, pte_t ptent, union mc_target *target)

{

	struct page *page = NULL;

	struct page_cgroup *pc;

	int ret = 0;

	swp_entry_t ent = { .val = 0 };



	if (pte_present(ptent))

		page = mc_handle_present_pte(vma, addr, ptent);

	else if (is_swap_pte(ptent))

		page = mc_handle_swap_pte(vma, addr, ptent, &ent);

	/* TODO: handle swap of shmes/tmpfs */



	if (!page && !ent.val)

		return 0;

	if (page) {

		pc = lookup_page_cgroup(page);

		/*
@@ -4221,8 +4243,8 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma, 
		if (!ret || !target)

			put_page(page);

	}

	/* throught */

	if (ent.val && do_swap_account && !ret &&

	/* There is a swap entry and a page doesn't exist or isn't charged */

	if (ent.val && !ret &&

			css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {

		ret = MC_TARGET_SWAP;

		if (target)