From a5f65109026b35b654b94fdcd26a971185a53adc Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Thu, 5 Nov 2015 18:47:26 -0800 Subject: [PATCH] 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: Naoya Horiguchi Cc: Andi Kleen Cc: Wanpeng Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 95882692e747..16a0ec385320 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -56,6 +56,7 @@ #include #include #include +#include #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)) -- 2.20.1