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Commit 33c2a174 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'stable/for-linus-3.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm 

Pull frontswap update from Konrad Rzeszutek Wilk:
 "Features:
   - Support exlusive get if backend is capable.
  Bug-fixes:
   - Fix compile warnings
   - Add comments/cleanup doc
   - Fix wrong if condition"

* tag 'stable/for-linus-3.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm:
  frontswap: support exclusive gets if tmem backend is capable
  mm: frontswap: fix a wrong if condition in frontswap_shrink
  mm/frontswap: fix uninit'ed variable warning
  mm/frontswap: cleanup doc and comment error
  mm: frontswap: remove unneeded headers
parents 88265322 e3483a5f

include/linux/frontswap.h

+2 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ extern struct frontswap_ops 
extern void frontswap_shrink(unsigned long);

extern unsigned long frontswap_curr_pages(void);

extern void frontswap_writethrough(bool);

#define FRONTSWAP_HAS_EXCLUSIVE_GETS

extern void frontswap_tmem_exclusive_gets(bool);



extern void __frontswap_init(unsigned type);

extern int __frontswap_store(struct page *page);

mm/frontswap.c

+30 −4
Original line number Diff line number Diff line
@@ -44,6 +44,13 @@ EXPORT_SYMBOL(frontswap_enabled); 
 */

static bool frontswap_writethrough_enabled __read_mostly;



/*

 * If enabled, the underlying tmem implementation is capable of doing

 * exclusive gets, so frontswap_load, on a successful tmem_get must

 * mark the page as no longer in frontswap AND mark it dirty.

 */

static bool frontswap_tmem_exclusive_gets_enabled __read_mostly;



#ifdef CONFIG_DEBUG_FS

/*

 * Counters available via /sys/kernel/debug/frontswap (if debugfs is
@@ -96,6 +103,15 @@ void frontswap_writethrough(bool enable) 
}

EXPORT_SYMBOL(frontswap_writethrough);



/*

 * Enable/disable frontswap exclusive gets (see above).

 */

void frontswap_tmem_exclusive_gets(bool enable)

{

	frontswap_tmem_exclusive_gets_enabled = enable;

}

EXPORT_SYMBOL(frontswap_tmem_exclusive_gets);



/*

 * Called when a swap device is swapon'd.

 */
@@ -174,8 +190,13 @@ int __frontswap_load(struct page *page) 
	BUG_ON(sis == NULL);

	if (frontswap_test(sis, offset))

		ret = frontswap_ops.load(type, offset, page);

	if (ret == 0)

	if (ret == 0) {

		inc_frontswap_loads();

		if (frontswap_tmem_exclusive_gets_enabled) {

			SetPageDirty(page);

			frontswap_clear(sis, offset);

		}

	}

	return ret;

}

EXPORT_SYMBOL(__frontswap_load);
@@ -263,6 +284,11 @@ static int __frontswap_unuse_pages(unsigned long total, unsigned long *unused, 
	return ret;

}



/*

 * Used to check if it's necessory and feasible to unuse pages.

 * Return 1 when nothing to do, 0 when need to shink pages,

 * error code when there is an error.

 */

static int __frontswap_shrink(unsigned long target_pages,

				unsigned long *pages_to_unuse,

				int *type)
@@ -275,7 +301,7 @@ static int __frontswap_shrink(unsigned long target_pages, 
	if (total_pages <= target_pages) {

		/* Nothing to do */

		*pages_to_unuse = 0;

		return 0;

		return 1;

	}

	total_pages_to_unuse = total_pages - target_pages;

	return __frontswap_unuse_pages(total_pages_to_unuse, pages_to_unuse, type);
@@ -292,7 +318,7 @@ static int __frontswap_shrink(unsigned long target_pages, 
void frontswap_shrink(unsigned long target_pages)

{

	unsigned long pages_to_unuse = 0;

	int type, ret;

	int uninitialized_var(type), ret;



	/*

	 * we don't want to hold swap_lock while doing a very
@@ -302,7 +328,7 @@ void frontswap_shrink(unsigned long target_pages) 
	spin_lock(&swap_lock);

	ret = __frontswap_shrink(target_pages, &pages_to_unuse, &type);

	spin_unlock(&swap_lock);

	if (ret == 0 && pages_to_unuse)

	if (ret == 0)

		try_to_unuse(type, true, pages_to_unuse);

	return;

}