Commit 2c1b4a5c authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
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[PATCH] swsusp: rework memory freeing on resume 



The following patch makes swsusp use the PG_nosave and PG_nosave_free flags to
mark pages that should be freed in case of an error during resume.

This allows us to simplify the code and to use swsusp_free() in all of the
swsusp's resume error paths, which makes them actually work.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a0f49651

arch/x86_64/kernel/suspend.c

+19 −65
Original line number Diff line number Diff line
@@ -147,57 +147,7 @@ extern int restore_image(void); 


pgd_t *temp_level4_pgt;



static void **pages;



static inline void *__add_page(void)

{

	void **c;



	c = (void **)get_usable_page(GFP_ATOMIC);

	if (c) {

		*c = pages;

		pages = c;

	}

	return c;

}



static inline void *__next_page(void)

{

	void **c;



	c = pages;

	if (c) {

		pages = *c;

		*c = NULL;

	}

	return c;

}



/*

 * Try to allocate as many usable pages as needed and daisy chain them.

 * If one allocation fails, free the pages allocated so far

 */

static int alloc_usable_pages(unsigned long n)

{

	void *p;



	pages = NULL;

	do

		if (!__add_page())

			break;

	while (--n);

	if (n) {

		p = __next_page();

		while (p) {

			free_page((unsigned long)p);

			p = __next_page();

		}

		return -ENOMEM;

	}

	return 0;

}



static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)

static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)

{

	long i, j;
@@ -211,7 +161,9 @@ static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long e 
		if (paddr >= end)

			break;



		pmd = (pmd_t *)__next_page();

		pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);

		if (!pmd)

			return -ENOMEM;

		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));

		for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {

			unsigned long pe;
@@ -223,13 +175,17 @@ static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long e 
			set_pmd(pmd, __pmd(pe));

		}

	}

	return 0;

}



static void set_up_temporary_mappings(void)

static int set_up_temporary_mappings(void)

{

	unsigned long start, end, next;

	int error;



	temp_level4_pgt = (pgd_t *)__next_page();

	temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);

	if (!temp_level4_pgt)

		return -ENOMEM;



	/* It is safe to reuse the original kernel mapping */

	set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
@@ -240,29 +196,27 @@ static void set_up_temporary_mappings(void) 
	end = (unsigned long)pfn_to_kaddr(end_pfn);



	for (; start < end; start = next) {

		pud_t *pud = (pud_t *)__next_page();

		pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);

		if (!pud)

			return -ENOMEM;

		next = start + PGDIR_SIZE;

		if (next > end)

			next = end;

		res_phys_pud_init(pud, __pa(start), __pa(next));

		if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))

			return error;

		set_pgd(temp_level4_pgt + pgd_index(start),

			mk_kernel_pgd(__pa(pud)));

	}

	return 0;

}



int swsusp_arch_resume(void)

{

	unsigned long n;

	int error;



	n = ((end_pfn << PAGE_SHIFT) + PUD_SIZE - 1) >> PUD_SHIFT;

	n += (n + PTRS_PER_PUD - 1) / PTRS_PER_PUD + 1;

	pr_debug("swsusp_arch_resume(): pages needed = %lu\n", n);

	if (alloc_usable_pages(n)) {

		free_eaten_memory();

		return -ENOMEM;

	}

	/* We have got enough memory and from now on we cannot recover */

	set_up_temporary_mappings();

	if ((error = set_up_temporary_mappings()))

		return error;

	restore_image();

	return 0;

}

include/linux/suspend.h

+1 −2
Original line number Diff line number Diff line
@@ -71,8 +71,7 @@ void restore_processor_state(void); 
struct saved_context;

void __save_processor_state(struct saved_context *ctxt);

void __restore_processor_state(struct saved_context *ctxt);

extern unsigned long get_usable_page(gfp_t gfp_mask);

extern void free_eaten_memory(void);

unsigned long get_safe_page(gfp_t gfp_mask);



/*

 * XXX: We try to keep some more pages free so that I/O operations succeed

kernel/power/disk.c

+7 −7
Original line number Diff line number Diff line
@@ -30,7 +30,6 @@ extern int swsusp_check(void); 
extern int swsusp_read(void);

extern void swsusp_close(void);

extern int swsusp_resume(void);

extern int swsusp_free(void);





static int noresume = 0;
@@ -252,14 +251,17 @@ static int software_resume(void) 


	pr_debug("PM: Reading swsusp image.\n");



	if ((error = swsusp_read()))

		goto Cleanup;

	if ((error = swsusp_read())) {

		swsusp_free();

		goto Thaw;

	}



	pr_debug("PM: Preparing devices for restore.\n");



	if ((error = device_suspend(PMSG_FREEZE))) {

		printk("Some devices failed to suspend\n");

		goto Free;

		swsusp_free();

		goto Thaw;

	}



	mb();
@@ -268,9 +270,7 @@ static int software_resume(void) 
	swsusp_resume();

	pr_debug("PM: Restore failed, recovering.n");

	device_resume();

 Free:

	swsusp_free();

 Cleanup:

 Thaw:

	unprepare_processes();

 Done:

	/* For success case, the suspend path will release the lock */

kernel/power/power.h

+1 −1
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ extern asmlinkage int swsusp_arch_suspend(void); 
extern asmlinkage int swsusp_arch_resume(void);



extern int restore_highmem(void);

extern void free_pagedir(struct pbe *pblist);

extern struct pbe * alloc_pagedir(unsigned nr_pages);

extern void create_pbe_list(struct pbe *pblist, unsigned nr_pages);

extern void swsusp_free(void);

extern int enough_swap(unsigned nr_pages);

kernel/power/snapshot.c

+1 −1
Original line number Diff line number Diff line
@@ -240,7 +240,7 @@ static void copy_data_pages(struct pbe *pblist) 
 *	free_pagedir - free pages allocated with alloc_pagedir()

 */



void free_pagedir(struct pbe *pblist)

static void free_pagedir(struct pbe *pblist)

{

	struct pbe *pbe;

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