From patchwork Tue Sep 22 13:56:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar Salvador X-Patchwork-Id: 11792619 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E69A3112C for ; Tue, 22 Sep 2020 13:57:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B152620936 for ; Tue, 22 Sep 2020 13:57:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B152620936 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3EB9D6B00BB; Tue, 22 Sep 2020 09:57:11 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 34F5E6B00BC; Tue, 22 Sep 2020 09:57:11 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1518D6B00BD; Tue, 22 Sep 2020 09:57:11 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0098.hostedemail.com [216.40.44.98]) by kanga.kvack.org (Postfix) with ESMTP id E63866B00BB for ; Tue, 22 Sep 2020 09:57:10 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A52DB1EF1 for ; Tue, 22 Sep 2020 13:57:10 +0000 (UTC) X-FDA: 77290849020.01.women78_25133d92714e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin01.hostedemail.com (Postfix) with ESMTP id 8C1271004AFBE for ; Tue, 22 Sep 2020 13:57:10 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,osalvador@suse.de,,RULES_HIT:30054:30070,0,RBL:195.135.220.15:@suse.de:.lbl8.mailshell.net-62.2.6.2 64.100.201.201;04y8m61oyn6f536swgnsdkqof7x4zoc7gfhjbaip4idunog1yyyfma5xycktu33.j793agadceudt3dr8y6etrwg5r9rjz4crrk8744nmcfe9exzntohhpx8qwnh9bt.s-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: women78_25133d92714e X-Filterd-Recvd-Size: 5535 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Tue, 22 Sep 2020 13:57:09 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id CF90FAFD2; Tue, 22 Sep 2020 13:57:45 +0000 (UTC) From: Oscar Salvador To: akpm@linux-foundation.org Cc: aris@ruivo.org, naoya.horiguchi@nec.com, mhocko@kernel.org, tony.luck@intel.com, cai@lca.pw, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Oscar Salvador Subject: [PATCH v7 08/14] mm,hwpoison: rework soft offline for free pages Date: Tue, 22 Sep 2020 15:56:44 +0200 Message-Id: <20200922135650.1634-9-osalvador@suse.de> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20200922135650.1634-1-osalvador@suse.de> References: <20200922135650.1634-1-osalvador@suse.de> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When trying to soft-offline a free page, we need to first take it off the buddy allocator. Once we know is out of reach, we can safely flag it as poisoned. take_page_off_buddy will be used to take a page meant to be poisoned off the buddy allocator. take_page_off_buddy calls break_down_buddy_pages, which splits a higher-order page in case our page belongs to one. Once the page is under our control, we call page_handle_poison to set it as poisoned and grab a refcount on it. Signed-off-by: Oscar Salvador Acked-by: Naoya Horiguchi --- include/linux/page-flags.h | 1 + mm/memory-failure.c | 18 ++++++---- mm/page_alloc.c | 68 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 6 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 7182103583d2..d0fdb59794d8 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -429,6 +429,7 @@ PAGEFLAG(HWPoison, hwpoison, PF_ANY) TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) extern bool set_hwpoison_free_buddy_page(struct page *page); +extern bool take_page_off_buddy(struct page *page); #else PAGEFLAG_FALSE(HWPoison) static inline bool set_hwpoison_free_buddy_page(struct page *page) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 9d80beb841a3..de274356f8c7 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -65,6 +65,13 @@ int sysctl_memory_failure_recovery __read_mostly = 1; atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0); +static void page_handle_poison(struct page *page) +{ + SetPageHWPoison(page); + page_ref_inc(page); + num_poisoned_pages_inc(); +} + #if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE) u32 hwpoison_filter_enable = 0; @@ -1884,14 +1891,13 @@ static int soft_offline_in_use_page(struct page *page, int flags) static int soft_offline_free_page(struct page *page) { - int rc = dissolve_free_huge_page(page); + int rc = -EBUSY; - if (!rc) { - if (set_hwpoison_free_buddy_page(page)) - num_poisoned_pages_inc(); - else - rc = -EBUSY; + if (!dissolve_free_huge_page(page) && take_page_off_buddy(page)) { + page_handle_poison(page); + rc = 0; } + return rc; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3c30be2e8e76..e02da891d8a9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8758,6 +8758,74 @@ bool is_free_buddy_page(struct page *page) } #ifdef CONFIG_MEMORY_FAILURE +/* + * Break down a higher-order page in sub-pages, and keep our target out of + * buddy allocator. + */ +static void break_down_buddy_pages(struct zone *zone, struct page *page, + struct page *target, int low, int high, + int migratetype) +{ + unsigned long size = 1 << high; + struct page *current_buddy, *next_page; + + while (high > low) { + high--; + size >>= 1; + + if (target >= &page[size]) { + next_page = page + size; + current_buddy = page; + } else { + next_page = page; + current_buddy = page + size; + } + + if (set_page_guard(zone, current_buddy, high, migratetype)) + continue; + + if (current_buddy != target) { + add_to_free_list(current_buddy, zone, high, migratetype); + set_page_order(current_buddy, high); + page = next_page; + } + } +} + +/* + * Take a page that will be marked as poisoned off the buddy allocator. + */ +bool take_page_off_buddy(struct page *page) +{ + struct zone *zone = page_zone(page); + unsigned long pfn = page_to_pfn(page); + unsigned long flags; + unsigned int order; + bool ret = false; + + spin_lock_irqsave(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + struct page *page_head = page - (pfn & ((1 << order) - 1)); + int buddy_order = page_order(page_head); + + if (PageBuddy(page_head) && buddy_order >= order) { + unsigned long pfn_head = page_to_pfn(page_head); + int migratetype = get_pfnblock_migratetype(page_head, + pfn_head); + + del_page_from_free_list(page_head, zone, buddy_order); + break_down_buddy_pages(zone, page_head, page, 0, + buddy_order, migratetype); + ret = true; + break; + } + if (page_count(page_head) > 0) + break; + } + spin_unlock_irqrestore(&zone->lock, flags); + return ret; +} + /* * Set PG_hwpoison flag if a given page is confirmed to be a free page. This * test is performed under the zone lock to prevent a race against page