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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A56F6C63798 for ; Thu, 19 Nov 2020 10:57:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2532E246F0 for ; Thu, 19 Nov 2020 10:57:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2532E246F0 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 A01136B006C; Thu, 19 Nov 2020 05:57:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E89B6B0070; Thu, 19 Nov 2020 05:57:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1DC6F6B0071; Thu, 19 Nov 2020 05:57:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0157.hostedemail.com [216.40.44.157]) by kanga.kvack.org (Postfix) with ESMTP id AB88E6B0070 for ; Thu, 19 Nov 2020 05:57:31 -0500 (EST) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 549F3180AD838 for ; Thu, 19 Nov 2020 10:57:31 +0000 (UTC) X-FDA: 77500866702.01.skirt75_170570127342 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin01.hostedemail.com (Postfix) with ESMTP id 377D310050002 for ; Thu, 19 Nov 2020 10:57:31 +0000 (UTC) X-HE-Tag: skirt75_170570127342 X-Filterd-Recvd-Size: 5558 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Thu, 19 Nov 2020 10:57:30 +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 9AF9CAE39; Thu, 19 Nov 2020 10:57:28 +0000 (UTC) From: Oscar Salvador To: akpm@linux-foundation.org Cc: n-horiguchi@ah.jp.nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: [PATCH 1/7] mm,hwpoison: Refactor get_any_page Date: Thu, 19 Nov 2020 11:57:10 +0100 Message-Id: <20201119105716.5962-2-osalvador@suse.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201119105716.5962-1-osalvador@suse.de> References: <20201119105716.5962-1-osalvador@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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 we want to grab a refcount via get_any_page, we call __get_any_page that calls get_hwpoison_page to get the actual refcount. get_any_page is only there because we have a sort of retry mechanism in case the page we met is unknown to us or if we raced with an allocation. Also __get_any_page prints some messages about the page type in case the page was a free page or the page type was unknown, but if anything, we only need to print a message in case the pagetype was unknown, as that is reporting an error down the chain. Let us merge get_any_page and __get_any_page, and let the message be printed in soft_offline_page. Signed-off-by: Oscar Salvador --- mm/memory-failure.c | 91 ++++++++++++++++++--------------------------- 1 file changed, 37 insertions(+), 54 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 869ece2a1de2..0d2323ba4b8e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1707,70 +1707,49 @@ EXPORT_SYMBOL(unpoison_memory); =20 /* * Safely get reference count of an arbitrary page. - * Returns 0 for a free page, -EIO for a zero refcount page - * that is not free, and 1 for any other page type. - * For 1 the page is returned with increased page count, otherwise not. + * Returns 0 for a free page, 1 for an in-use page, -EIO for a page-type= we + * cannot handle and -EBUSY if we raced with an allocation. + * We only incremented refcount in case the page was already in-use and = it is + * a known type we can handle. */ -static int __get_any_page(struct page *p, unsigned long pfn, int flags) +static int get_any_page(struct page *p, unsigned long pfn, int flags) { - int ret; + int ret =3D 0, pass =3D 0; =20 if (flags & MF_COUNT_INCREASED) return 1; =20 - /* - * When the target page is a free hugepage, just remove it - * from free hugepage list. - */ +try_again: if (!get_hwpoison_page(p)) { - if (PageHuge(p)) { - pr_info("%s: %#lx free huge page\n", __func__, pfn); - ret =3D 0; - } else if (is_free_buddy_page(p)) { - pr_info("%s: %#lx free buddy page\n", __func__, pfn); - ret =3D 0; - } else if (page_count(p)) { - /* raced with allocation */ + if (page_count(p)) { + /* We raced with an allocation, retry. */ + if (pass++ < 3) + goto try_again; ret =3D -EBUSY; - } else { - pr_info("%s: %#lx: unknown zero refcount page type %lx\n", - __func__, pfn, p->flags); + } else if (!PageHuge(p) && !is_free_buddy_page(p)) { + /* We raced with put_page, retry. */ + if (pass++ < 3) + goto try_again; ret =3D -EIO; } } else { - /* Not a free page */ - ret =3D 1; - } - return ret; -} - -static int get_any_page(struct page *page, unsigned long pfn, int flags) -{ - int ret =3D __get_any_page(page, pfn, flags); - - if (ret =3D=3D -EBUSY) - ret =3D __get_any_page(page, pfn, flags); - - if (ret =3D=3D 1 && !PageHuge(page) && - !PageLRU(page) && !__PageMovable(page)) { - /* - * Try to free it. - */ - put_page(page); - shake_page(page, 1); - - /* - * Did it turn free? - */ - ret =3D __get_any_page(page, pfn, 0); - if (ret =3D=3D 1 && !PageLRU(page)) { - /* Drop page reference which is from __get_any_page() */ - put_page(page); - pr_info("soft_offline: %#lx: unknown non LRU page type %lx (%pGp)\n", - pfn, page->flags, &page->flags); - return -EIO; + if (PageHuge(p) || PageLRU(p) || __PageMovable(p)) { + ret =3D 1; + } else { + /* + * A page we cannot handle. Check whether we can turn + * it into something we can handle. + */ + if (pass++ < 3) { + put_page(p); + shake_page(p, 1); + goto try_again; + } + put_page(p); + ret =3D -EIO; } } + return ret; } =20 @@ -1939,7 +1918,7 @@ int soft_offline_page(unsigned long pfn, int flags) return -EIO; =20 if (PageHWPoison(page)) { - pr_info("soft offline: %#lx page already poisoned\n", pfn); + pr_info("%s: %#lx page already poisoned\n", __func__, pfn); if (flags & MF_COUNT_INCREASED) put_page(page); return 0; @@ -1950,13 +1929,17 @@ int soft_offline_page(unsigned long pfn, int flag= s) ret =3D get_any_page(page, pfn, flags); put_online_mems(); =20 - if (ret > 0) + if (ret > 0) { ret =3D soft_offline_in_use_page(page); - else if (ret =3D=3D 0) + } else if (ret =3D=3D 0) { if (soft_offline_free_page(page) && try_again) { try_again =3D false; goto retry; } + } else if (ret =3D=3D -EIO) { + pr_info("%s: %#lx: unknown page type: %lx (%pGP)\n", + __func__, pfn, page->flags, &page->flags); + } =20 return ret; } --=20 2.26.2