Commit 75f6d6d2 authored by Minchan Kim's avatar Minchan Kim Committed by Linus Torvalds
Browse files

mm, THP, swap: unify swap slot free functions to put_swap_page 

Now, get_swap_page takes struct page and allocates swap space according
to page size(ie, normal or THP) so it would be more cleaner to introduce
put_swap_page which is a counter function of get_swap_page.  Then, it
calls right swap slot free function depending on page's size.

[ying.huang@intel.com: minor cleanup and fix]
Link: http://lkml.kernel.org/r/20170515112522.32457-3-ying.huang@intel.com


Signed-off-by: default avatarMinchan Kim <minchan@kernel.org>
Signed-off-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 38d8b4e6

include/linux/swap.h

+2 −10
Original line number Diff line number Diff line
@@ -387,6 +387,7 @@ static inline long get_nr_swap_pages(void) 


extern void si_swapinfo(struct sysinfo *);

extern swp_entry_t get_swap_page(struct page *page);

extern void put_swap_page(struct page *page, swp_entry_t entry);

extern swp_entry_t get_swap_page_of_type(int);

extern int get_swap_pages(int n, bool cluster, swp_entry_t swp_entries[]);

extern int add_swap_count_continuation(swp_entry_t, gfp_t);
@@ -394,7 +395,6 @@ extern void swap_shmem_alloc(swp_entry_t); 
extern int swap_duplicate(swp_entry_t);

extern int swapcache_prepare(swp_entry_t);

extern void swap_free(swp_entry_t);

extern void swapcache_free(swp_entry_t);

extern void swapcache_free_entries(swp_entry_t *entries, int n);

extern int free_swap_and_cache(swp_entry_t);

extern int swap_type_of(dev_t, sector_t, struct block_device **);
@@ -453,7 +453,7 @@ static inline void swap_free(swp_entry_t swp) 
{

}



static inline void swapcache_free(swp_entry_t swp)

static inline void put_swap_page(struct page *page, swp_entry_t swp)

{

}
@@ -578,13 +578,5 @@ static inline bool mem_cgroup_swap_full(struct page *page) 
}

#endif



#ifdef CONFIG_THP_SWAP

extern void swapcache_free_cluster(swp_entry_t entry);

#else

static inline void swapcache_free_cluster(swp_entry_t entry)

{

}

#endif



#endif /* __KERNEL__*/

#endif /* _LINUX_SWAP_H */

mm/shmem.c

+1 −1
Original line number Diff line number Diff line
@@ -1327,7 +1327,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) 


	mutex_unlock(&shmem_swaplist_mutex);

free_swap:

	swapcache_free(swap);

	put_swap_page(page, swap);

redirty:

	set_page_dirty(page);

	if (wbc->for_reclaim)

mm/swap_state.c

+3 −10
Original line number Diff line number Diff line
@@ -231,10 +231,7 @@ retry: 
	return 1;



fail_free:

	if (PageTransHuge(page))

		swapcache_free_cluster(entry);

	else

		swapcache_free(entry);

	put_swap_page(page, entry);

fail:

	if (PageTransHuge(page) && !split_huge_page_to_list(page, list))

		goto retry;
@@ -259,11 +256,7 @@ void delete_from_swap_cache(struct page *page) 
	__delete_from_swap_cache(page);

	spin_unlock_irq(&address_space->tree_lock);



	if (PageTransHuge(page))

		swapcache_free_cluster(entry);

	else

		swapcache_free(entry);



	put_swap_page(page, entry);

	page_ref_sub(page, hpage_nr_pages(page));

}
@@ -415,7 +408,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 
		 * add_to_swap_cache() doesn't return -EEXIST, so we can safely

		 * clear SWAP_HAS_CACHE flag.

		 */

		swapcache_free(entry);

		put_swap_page(new_page, entry);

	} while (err != -ENOMEM);



	if (new_page)

mm/swapfile.c

+14 −2
Original line number Diff line number Diff line
@@ -1148,7 +1148,7 @@ void swap_free(swp_entry_t entry) 
/*

 * Called after dropping swapcache to decrease refcnt to swap entries.

 */

void swapcache_free(swp_entry_t entry)

static void swapcache_free(swp_entry_t entry)

{

	struct swap_info_struct *p;
@@ -1160,7 +1160,7 @@ void swapcache_free(swp_entry_t entry) 
}



#ifdef CONFIG_THP_SWAP

void swapcache_free_cluster(swp_entry_t entry)

static void swapcache_free_cluster(swp_entry_t entry)

{

	unsigned long offset = swp_offset(entry);

	unsigned long idx = offset / SWAPFILE_CLUSTER;
@@ -1184,8 +1184,20 @@ void swapcache_free_cluster(swp_entry_t entry) 
	swap_free_cluster(si, idx);

	spin_unlock(&si->lock);

}

#else

static inline void swapcache_free_cluster(swp_entry_t entry)

{

}

#endif /* CONFIG_THP_SWAP */



void put_swap_page(struct page *page, swp_entry_t entry)

{

	if (!PageTransHuge(page))

		swapcache_free(entry);

	else

		swapcache_free_cluster(entry);

}



void swapcache_free_entries(swp_entry_t *entries, int n)

{

	struct swap_info_struct *p, *prev;

mm/vmscan.c

+1 −1
Original line number Diff line number Diff line
@@ -708,7 +708,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, 
		mem_cgroup_swapout(page, swap);

		__delete_from_swap_cache(page);

		spin_unlock_irqrestore(&mapping->tree_lock, flags);

		swapcache_free(swap);

		put_swap_page(page, swap);

	} else {

		void (*freepage)(struct page *);

		void *shadow = NULL;

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