Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756171AbYLAAqp (ORCPT ); Sun, 30 Nov 2008 19:46:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753835AbYLAAqh (ORCPT ); Sun, 30 Nov 2008 19:46:37 -0500 Received: from extu-mxob-1.symantec.com ([216.10.194.28]:34091 "EHLO extu-mxob-1.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752627AbYLAAqg (ORCPT ); Sun, 30 Nov 2008 19:46:36 -0500 Date: Mon, 1 Dec 2008 00:46:53 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@blonde.site To: Andrew Morton cc: Nick Piggin , Dave Jones , Arjan van de Ven , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 7/8] badpage: ratelimit print_bad_pte and bad_page In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2908 Lines: 92 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 --- mm/memory.c | 23 +++++++++++++++++++++++ mm/page_alloc.c | 26 +++++++++++++++++++++++++- 2 files changed, 48 insertions(+), 1 deletion(-) --- badpage6/mm/memory.c 2008-11-28 20:40:48.000000000 +0000 +++ badpage7/mm/memory.c 2008-11-28 20:40:50.000000000 +0000 @@ -383,6 +383,29 @@ static void print_bad_pte(struct vm_area 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); --- badpage6/mm/page_alloc.c 2008-11-28 20:40:42.000000000 +0000 +++ badpage7/mm/page_alloc.c 2008-11-28 20:40:50.000000000 +0000 @@ -223,6 +223,30 @@ static inline int bad_range(struct zone 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/