Commit a5f65109 authored by Naoya Horiguchi's avatar Naoya Horiguchi Committed by Linus Torvalds
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mm: hwpoison: ratelimit messages from unpoison_memory() 



Currently kernel prints out results of every single unpoison event, which
i= s not necessary because unpoison is purely a testing feature and
testers can = get little or no information from lots of lines of unpoison
log storm.  So this patch ratelimits printk in unpoison_memory().

This patch introduces a file local ratelimit_state, which adds 64 bytes to
memory-failure.o.  If we apply pr_info_ratelimited() for 8 callsite below,
2= 56 bytes is added, so it's a win.

Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent aa750fd7

mm/memory-failure.c

+25 −9
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ 
#include <linux/memory_hotplug.h>

#include <linux/mm_inline.h>

#include <linux/kfifo.h>

#include <linux/ratelimit.h>

#include "internal.h"

#include "ras/ras_event.h"
@@ -1403,6 +1404,12 @@ static int __init memory_failure_init(void) 
}

core_initcall(memory_failure_init);



#define unpoison_pr_info(fmt, pfn, rs)			\

({							\

	if (__ratelimit(rs))				\

		pr_info(fmt, pfn);			\

})



/**

 * unpoison_memory - Unpoison a previously poisoned page

 * @pfn: Page number of the to be unpoisoned page
@@ -1421,6 +1428,8 @@ int unpoison_memory(unsigned long pfn) 
	struct page *p;

	int freeit = 0;

	unsigned int nr_pages;

	static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,

					DEFAULT_RATELIMIT_BURST);



	if (!pfn_valid(pfn))

		return -ENXIO;
@@ -1429,23 +1438,26 @@ int unpoison_memory(unsigned long pfn) 
	page = compound_head(p);



	if (!PageHWPoison(p)) {

		pr_info("MCE: Page was already unpoisoned %#lx\n", pfn);

		unpoison_pr_info("MCE: Page was already unpoisoned %#lx\n",

				 pfn, &unpoison_rs);

		return 0;

	}



	if (page_count(page) > 1) {

		pr_info("MCE: Someone grabs the hwpoison page %#lx\n", pfn);

		unpoison_pr_info("MCE: Someone grabs the hwpoison page %#lx\n",

				 pfn, &unpoison_rs);

		return 0;

	}



	if (page_mapped(page)) {

		pr_info("MCE: Someone maps the hwpoison page %#lx\n", pfn);

		unpoison_pr_info("MCE: Someone maps the hwpoison page %#lx\n",

				 pfn, &unpoison_rs);

		return 0;

	}



	if (page_mapping(page)) {

		pr_info("MCE: the hwpoison page has non-NULL mapping %#lx\n",

			pfn);

		unpoison_pr_info("MCE: the hwpoison page has non-NULL mapping %#lx\n",

				 pfn, &unpoison_rs);

		return 0;

	}
@@ -1455,7 +1467,8 @@ int unpoison_memory(unsigned long pfn) 
	 * In such case, we yield to memory_failure() and make unpoison fail.

	 */

	if (!PageHuge(page) && PageTransHuge(page)) {

		pr_info("MCE: Memory failure is now running on %#lx\n", pfn);

		unpoison_pr_info("MCE: Memory failure is now running on %#lx\n",

				 pfn, &unpoison_rs);

		return 0;

	}
@@ -1469,12 +1482,14 @@ int unpoison_memory(unsigned long pfn) 
		 * to the end.

		 */

		if (PageHuge(page)) {

			pr_info("MCE: Memory failure is now running on free hugepage %#lx\n", pfn);

			unpoison_pr_info("MCE: Memory failure is now running on free hugepage %#lx\n",

					 pfn, &unpoison_rs);

			return 0;

		}

		if (TestClearPageHWPoison(p))

			num_poisoned_pages_dec();

		pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn);

		unpoison_pr_info("MCE: Software-unpoisoned free page %#lx\n",

				 pfn, &unpoison_rs);

		return 0;

	}
@@ -1486,7 +1501,8 @@ int unpoison_memory(unsigned long pfn) 
	 * the free buddy page pool.

	 */

	if (TestClearPageHWPoison(page)) {

		pr_info("MCE: Software-unpoisoned page %#lx\n", pfn);

		unpoison_pr_info("MCE: Software-unpoisoned page %#lx\n",

				 pfn, &unpoison_rs);

		num_poisoned_pages_sub(nr_pages);

		freeit = 1;

		if (PageHuge(page))

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