From d936cf9b39b06c8d2e0d7fb5e7b4f176e18dec69 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 6 Jan 2009 14:40:12 -0800 Subject: [PATCH] badpage: ratelimit print_bad_pte and bad_page print_bad_pte() and bad_page() might each need ratelimiting - especially for their dump_stacks, almost never of interest, yet not quite dispensible. Correlating corruption across neighbouring entries can be very helpful, so allow a burst of 60 reports before keeping quiet for the remainder of that minute (or allow a steady drip of one report per second). Signed-off-by: Hugh Dickins Cc: Nick Piggin Cc: Christoph Lameter Cc: Mel Gorman Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 23 +++++++++++++++++++++++ mm/page_alloc.c | 26 +++++++++++++++++++++++++- 2 files changed, 48 insertions(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index 0f9abbaf618c..b12888c1b4e3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -383,6 +383,29 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd = pmd_offset(pud, addr); struct address_space *mapping; pgoff_t index; + static unsigned long resume; + static unsigned long nr_shown; + static unsigned long nr_unshown; + + /* + * Allow a burst of 60 reports, then keep quiet for that minute; + * or allow a steady drip of one report per second. + */ + if (nr_shown == 60) { + if (time_before(jiffies, resume)) { + nr_unshown++; + return; + } + if (nr_unshown) { + printk(KERN_EMERG + "Bad page map: %lu messages suppressed\n", + nr_unshown); + nr_unshown = 0; + } + nr_shown = 0; + } + if (nr_shown++ == 0) + resume = jiffies + 60 * HZ; mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL; index = linear_page_index(vma, addr); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 755c99a0ac71..d1a80f652c6f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -223,6 +223,30 @@ static inline int bad_range(struct zone *zone, struct page *page) static void bad_page(struct page *page) { + static unsigned long resume; + static unsigned long nr_shown; + static unsigned long nr_unshown; + + /* + * Allow a burst of 60 reports, then keep quiet for that minute; + * or allow a steady drip of one report per second. + */ + if (nr_shown == 60) { + if (time_before(jiffies, resume)) { + nr_unshown++; + goto out; + } + if (nr_unshown) { + printk(KERN_EMERG + "Bad page state: %lu messages suppressed\n", + nr_unshown); + nr_unshown = 0; + } + nr_shown = 0; + } + if (nr_shown++ == 0) + resume = jiffies + 60 * HZ; + printk(KERN_EMERG "Bad page state in process %s pfn:%05lx\n", current->comm, page_to_pfn(page)); printk(KERN_EMERG @@ -232,7 +256,7 @@ static void bad_page(struct page *page) printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"); dump_stack(); - +out: /* Leave bad fields for debug, except PageBuddy could make trouble */ __ClearPageBuddy(page); add_taint(TAINT_BAD_PAGE);