Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d936cf9b authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

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: default avatarHugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent edc315fd

mm/memory.c

+23 −0
Original line number Diff line number Diff line
@@ -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);

mm/page_alloc.c

+25 −1
Original line number Diff line number Diff line
@@ -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);