From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB064C433E7 for ; Thu, 16 Jul 2020 12:38:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 71821207BB for ; Thu, 16 Jul 2020 12:38:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 71821207BB 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 D34278D0014; Thu, 16 Jul 2020 08:38:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D0B918D000D; Thu, 16 Jul 2020 08:38:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFB7A8D0014; Thu, 16 Jul 2020 08:38:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0133.hostedemail.com [216.40.44.133]) by kanga.kvack.org (Postfix) with ESMTP id A9C9D8D000D for ; Thu, 16 Jul 2020 08:38:36 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6E3C382499B9 for ; Thu, 16 Jul 2020 12:38:36 +0000 (UTC) X-FDA: 77043892632.15.home06_240024626f02 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id 36F711814B0C8 for ; Thu, 16 Jul 2020 12:38:36 +0000 (UTC) X-HE-Tag: home06_240024626f02 X-Filterd-Recvd-Size: 5610 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Thu, 16 Jul 2020 12:38:35 +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 76A9CB943; Thu, 16 Jul 2020 12:38:38 +0000 (UTC) From: Oscar Salvador To: akpm@linux-foundation.org Cc: mhocko@suse.com, linux-mm@kvack.org, mike.kravetz@oracle.com, david@redhat.com, aneesh.kumar@linux.vnet.ibm.com, naoya.horiguchi@nec.com, linux-kernel@vger.kernel.org, Oscar Salvador , Oscar Salvador Subject: [PATCH v4 11/15] mm,hwpoison: Rework soft offline for free pages Date: Thu, 16 Jul 2020 14:38:05 +0200 Message-Id: <20200716123810.25292-12-osalvador@suse.de> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20200716123810.25292-1-osalvador@suse.de> References: <20200716123810.25292-1-osalvador@suse.de> X-Rspamd-Queue-Id: 36F711814B0C8 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 Signed-off-by: Naoya Horiguchi --- include/linux/page-flags.h | 1 + mm/memory-failure.c | 17 +++++++--- mm/page_alloc.c | 68 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 5 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 276140c94f4a..01baf6d426ff 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -425,6 +425,7 @@ PAGEFLAG_FALSE(Uncached) PAGEFLAG(HWPoison, hwpoison, PF_ANY) TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) +extern bool take_page_off_buddy(struct page *page); extern bool set_hwpoison_free_buddy_page(struct page *page); #else PAGEFLAG_FALSE(HWPoison) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2e244d5b83e0..caf012d34607 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; @@ -1876,14 +1883,14 @@ static int soft_offline_in_use_page(struct page *page) static int soft_offline_free_page(struct page *page) { + int rc = -EBUSY; int rc = dissolve_free_huge_page(page); - 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 9e07a5d2d30d..4fa0e0887c07 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8777,6 +8777,74 @@ 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 -- 2.26.2