From 2c1b4a5ca48831595979a850f40ced8e7da026f8 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 30 Oct 2005 14:59:58 -0800 Subject: [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 --- kernel/power/swsusp.c | 110 +++++++++++++++++--------------------------------- 1 file changed, 36 insertions(+), 74 deletions(-) (limited to 'kernel/power/swsusp.c') diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index f6abfdb0a02..50667f4f3a2 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; } -- cgit v1.2.3