From 2c1b4a5ca48831595979a850f40ced8e7da026f8 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 30 Oct 2005 14:59:58 -0800 Subject: [PATCH] [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: Rafael J. Wysocki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/suspend.c | 84 ++++++-------------------- include/linux/suspend.h | 3 +- kernel/power/disk.c | 14 ++--- kernel/power/power.h | 2 +- kernel/power/snapshot.c | 2 +- kernel/power/swsusp.c | 110 ++++++++++++----------------------- 6 files changed, 65 insertions(+), 150 deletions(-) diff --git a/arch/x86_64/kernel/suspend.c b/arch/x86_64/kernel/suspend.c index 02516823f5..fd2bef7808 100644 --- a/arch/x86_64/kernel/suspend.c +++ b/arch/x86_64/kernel/suspend.c @@ -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; } diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 380915e956..a61c04f804 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -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 diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 761956e813..44ef5e799d 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -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 */ diff --git a/kernel/power/power.h b/kernel/power/power.h index 28afcb0901..d4fd96a135 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -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); diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 03916cf3ff..84e686bdb4 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -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; diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index f6abfdb0a0..50667f4f3a 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -629,6 +629,11 @@ int swsusp_resume(void) * execution continues at place where swsusp_arch_suspend was called */ BUG_ON(!error); + /* The only reason why swsusp_arch_resume() can fail is memory being + * very tight, so we have to free it as soon as we can to avoid + * subsequent failures + */ + swsusp_free(); restore_processor_state(); restore_highmem(); touch_softlockup_watchdog(); @@ -644,54 +649,28 @@ int swsusp_resume(void) * * We don't know which pages are usable until we allocate them. * - * Allocated but unusable (ie eaten) memory pages are linked together - * to create a list, so that we can free them easily - * - * We could have used a type other than (void *) - * for this purpose, but ... + * Allocated but unusable (ie eaten) memory pages are marked so that + * swsusp_free() can release them */ -static void **eaten_memory = NULL; -static inline void eat_page(void *page) -{ - void **c; - - c = eaten_memory; - eaten_memory = page; - *eaten_memory = c; -} - -unsigned long get_usable_page(gfp_t gfp_mask) +unsigned long get_safe_page(gfp_t gfp_mask) { unsigned long m; - m = get_zeroed_page(gfp_mask); - while (!PageNosaveFree(virt_to_page(m))) { - eat_page((void *)m); + do { m = get_zeroed_page(gfp_mask); - if (!m) - break; + if (m && PageNosaveFree(virt_to_page(m))) + /* This is for swsusp_free() */ + SetPageNosave(virt_to_page(m)); + } while (m && PageNosaveFree(virt_to_page(m))); + if (m) { + /* This is for swsusp_free() */ + SetPageNosave(virt_to_page(m)); + SetPageNosaveFree(virt_to_page(m)); } return m; } -void free_eaten_memory(void) -{ - unsigned long m; - void **c; - int i = 0; - - c = eaten_memory; - while (c) { - m = (unsigned long)c; - c = *c; - free_page(m); - i++; - } - eaten_memory = NULL; - pr_debug("swsusp: %d unused pages freed\n", i); -} - /** * check_pagedir - We ensure here that pages that the PBEs point to * won't collide with pages where we're going to restore from the loaded @@ -709,7 +688,7 @@ static int check_pagedir(struct pbe *pblist) p->address = 0UL; for_each_pbe (p, pblist) { - p->address = get_usable_page(GFP_ATOMIC); + p->address = get_safe_page(GFP_ATOMIC); if (!p->address) return -ENOMEM; } @@ -728,7 +707,7 @@ static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist) unsigned long zone_pfn; struct pbe *pbpage, *tail, *p; void *m; - int rel = 0, error = 0; + int rel = 0; if (!pblist) /* a sanity check */ return NULL; @@ -736,41 +715,37 @@ static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist) pr_debug("swsusp: Relocating pagedir (%lu pages to check)\n", swsusp_info.pagedir_pages); - /* Set page flags */ + /* Clear page flags */ for_each_zone (zone) { for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) - SetPageNosaveFree(pfn_to_page(zone_pfn + + if (pfn_valid(zone_pfn + zone->zone_start_pfn)) + ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn)); } - /* Clear orig addresses */ + /* Mark orig addresses */ for_each_pbe (p, pblist) - ClearPageNosaveFree(virt_to_page(p->orig_address)); + SetPageNosaveFree(virt_to_page(p->orig_address)); tail = pblist + PB_PAGE_SKIP; /* Relocate colliding pages */ for_each_pb_page (pbpage, pblist) { - if (!PageNosaveFree(virt_to_page((unsigned long)pbpage))) { - m = (void *)get_usable_page(GFP_ATOMIC | __GFP_COLD); - if (!m) { - error = -ENOMEM; - break; - } + if (PageNosaveFree(virt_to_page((unsigned long)pbpage))) { + m = (void *)get_safe_page(GFP_ATOMIC | __GFP_COLD); + if (!m) + return NULL; memcpy(m, (void *)pbpage, PAGE_SIZE); if (pbpage == pblist) pblist = (struct pbe *)m; else tail->next = (struct pbe *)m; - - eat_page((void *)pbpage); pbpage = (struct pbe *)m; /* We have to link the PBEs again */ - for (p = pbpage; p < pbpage + PB_PAGE_SKIP; p++) if (p->next) /* needed to save the end */ p->next = p + 1; @@ -780,15 +755,13 @@ static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist) tail = pbpage + PB_PAGE_SKIP; } - if (error) { - printk("\nswsusp: Out of memory\n\n"); - free_pagedir(pblist); - free_eaten_memory(); - pblist = NULL; - /* Is this even worth handling? It should never ever happen, and we - have just lost user's state, anyway... */ - } else - printk("swsusp: Relocated %d pages\n", rel); + /* This is for swsusp_free() */ + for_each_pb_page (pbpage, pblist) { + SetPageNosave(virt_to_page(pbpage)); + SetPageNosaveFree(virt_to_page(pbpage)); + } + + printk("swsusp: Relocated %d pages\n", rel); return pblist; } @@ -1006,9 +979,7 @@ static int read_pagedir(struct pbe *pblist) break; } - if (error) - free_pagedir(pblist); - else + if (!error) BUG_ON(i != swsusp_info.pagedir_pages); return error; @@ -1051,15 +1022,6 @@ static int read_suspend_image(void) if (!error) error = data_read(pagedir_nosave); - if (error) { /* We fail cleanly */ - free_eaten_memory(); - for_each_pbe (p, pagedir_nosave) - if (p->address) { - free_page(p->address); - p->address = 0UL; - } - free_pagedir(pagedir_nosave); - } return error; } -- 2.39.5