Commit f0e45fb4 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm: memcontrol: drop unused try/commit/cancel charge API 

There are no more users. RIP in peace.

[arnd@arndb.de: fix an unused-function warning]
  Link: http://lkml.kernel.org/r/20200528095640.151454-1-arnd@arndb.de


Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-14-hannes@cmpxchg.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9d82c694

include/linux/memcontrol.h

+0 −36
Original line number Diff line number Diff line
@@ -355,14 +355,6 @@ static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg, 
enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,

						struct mem_cgroup *memcg);



int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,

			  gfp_t gfp_mask, struct mem_cgroup **memcgp);

int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm,

			  gfp_t gfp_mask, struct mem_cgroup **memcgp);

void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,

			      bool lrucare);

void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg);



int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask,

		      bool lrucare);
@@ -846,34 +838,6 @@ static inline enum mem_cgroup_protection mem_cgroup_protected( 
	return MEMCG_PROT_NONE;

}



static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,

					gfp_t gfp_mask,

					struct mem_cgroup **memcgp)

{

	*memcgp = NULL;

	return 0;

}



static inline int mem_cgroup_try_charge_delay(struct page *page,

					      struct mm_struct *mm,

					      gfp_t gfp_mask,

					      struct mem_cgroup **memcgp)

{

	*memcgp = NULL;

	return 0;

}



static inline void mem_cgroup_commit_charge(struct page *page,

					    struct mem_cgroup *memcg,

					    bool lrucare)

{

}



static inline void mem_cgroup_cancel_charge(struct page *page,

					    struct mem_cgroup *memcg)

{

}



static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,

				    gfp_t gfp_mask, bool lrucare)

{

mm/memcontrol.c

+17 −111
Original line number Diff line number Diff line
@@ -2641,6 +2641,7 @@ done_restock: 
	return 0;

}



#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)

static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)

{

	if (mem_cgroup_is_root(memcg))
@@ -2652,6 +2653,7 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) 


	css_put_many(&memcg->css, nr_pages);

}

#endif



static void lock_page_lru(struct page *page, int *isolated)

{
@@ -6499,29 +6501,26 @@ out: 
}



/**

 * mem_cgroup_try_charge - try charging a page

 * mem_cgroup_charge - charge a newly allocated page to a cgroup

 * @page: page to charge

 * @mm: mm context of the victim

 * @gfp_mask: reclaim mode

 * @memcgp: charged memcg return

 * @lrucare: page might be on the LRU already

 *

 * Try to charge @page to the memcg that @mm belongs to, reclaiming

 * pages according to @gfp_mask if necessary.

 *

 * Returns 0 on success, with *@memcgp pointing to the charged memcg.

 * Otherwise, an error code is returned.

 *

 * After page->mapping has been set up, the caller must finalize the

 * charge with mem_cgroup_commit_charge().  Or abort the transaction

 * with mem_cgroup_cancel_charge() in case page instantiation fails.

 * Returns 0 on success. Otherwise, an error code is returned.

 */

int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,

			  gfp_t gfp_mask, struct mem_cgroup **memcgp)

int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask,

		      bool lrucare)

{

	unsigned int nr_pages = hpage_nr_pages(page);

	struct mem_cgroup *memcg = NULL;

	int ret = 0;



	VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);



	if (mem_cgroup_disabled())

		goto out;
@@ -6553,56 +6552,8 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, 
		memcg = get_mem_cgroup_from_mm(mm);



	ret = try_charge(memcg, gfp_mask, nr_pages);



	css_put(&memcg->css);

out:

	*memcgp = memcg;

	return ret;

}



int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm,

			  gfp_t gfp_mask, struct mem_cgroup **memcgp)

{

	int ret;



	ret = mem_cgroup_try_charge(page, mm, gfp_mask, memcgp);

	if (*memcgp)

		cgroup_throttle_swaprate(page, gfp_mask);

	return ret;

}



/**

 * mem_cgroup_commit_charge - commit a page charge

 * @page: page to charge

 * @memcg: memcg to charge the page to

 * @lrucare: page might be on LRU already

 *

 * Finalize a charge transaction started by mem_cgroup_try_charge(),

 * after page->mapping has been set up.  This must happen atomically

 * as part of the page instantiation, i.e. under the page table lock

 * for anonymous pages, under the page lock for page and swap cache.

 *

 * In addition, the page must not be on the LRU during the commit, to

 * prevent racing with task migration.  If it might be, use @lrucare.

 *

 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.

 */

void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,

			      bool lrucare)

{

	unsigned int nr_pages = hpage_nr_pages(page);



	VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);



	if (mem_cgroup_disabled())

		return;

	/*

	 * Swap faults will attempt to charge the same page multiple

	 * times.  But reuse_swap_page() might have removed the page

	 * from swapcache already, so we can't check PageSwapCache().

	 */

	if (!memcg)

		return;

	if (ret)

		goto out_put;



	commit_charge(page, memcg, lrucare);
@@ -6620,55 +6571,11 @@ void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, 
		 */

		mem_cgroup_uncharge_swap(entry, nr_pages);

	}

}



/**

 * mem_cgroup_cancel_charge - cancel a page charge

 * @page: page to charge

 * @memcg: memcg to charge the page to

 *

 * Cancel a charge transaction started by mem_cgroup_try_charge().

 */

void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg)

{

	unsigned int nr_pages = hpage_nr_pages(page);



	if (mem_cgroup_disabled())

		return;

	/*

	 * Swap faults will attempt to charge the same page multiple

	 * times.  But reuse_swap_page() might have removed the page

	 * from swapcache already, so we can't check PageSwapCache().

	 */

	if (!memcg)

		return;



	cancel_charge(memcg, nr_pages);

}



/**

 * mem_cgroup_charge - charge a newly allocated page to a cgroup

 * @page: page to charge

 * @mm: mm context of the victim

 * @gfp_mask: reclaim mode

 * @lrucare: page might be on the LRU already

 *

 * Try to charge @page to the memcg that @mm belongs to, reclaiming

 * pages according to @gfp_mask if necessary.

 *

 * Returns 0 on success. Otherwise, an error code is returned.

 */

int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask,

		      bool lrucare)

{

	struct mem_cgroup *memcg;

	int ret;



	ret = mem_cgroup_try_charge(page, mm, gfp_mask, &memcg);

	if (ret)

out_put:

	css_put(&memcg->css);

out:

	return ret;

	mem_cgroup_commit_charge(page, memcg, lrucare);

	return 0;

}



struct uncharge_gather {
@@ -6773,8 +6680,7 @@ static void uncharge_list(struct list_head *page_list) 
 * mem_cgroup_uncharge - uncharge a page

 * @page: page to uncharge

 *

 * Uncharge a page previously charged with mem_cgroup_try_charge() and

 * mem_cgroup_commit_charge().

 * Uncharge a page previously charged with mem_cgroup_charge().

 */

void mem_cgroup_uncharge(struct page *page)

{
@@ -6797,7 +6703,7 @@ void mem_cgroup_uncharge(struct page *page) 
 * @page_list: list of pages to uncharge

 *

 * Uncharge a list of pages previously charged with

 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().

 * mem_cgroup_charge().

 */

void mem_cgroup_uncharge_list(struct list_head *page_list)

{

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