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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06D01C43334 for ; Thu, 30 Jun 2022 02:28:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 93C978E0005; Wed, 29 Jun 2022 22:28:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EC8A8E0001; Wed, 29 Jun 2022 22:28:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78D1E8E0005; Wed, 29 Jun 2022 22:28:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 68AEF8E0001 for ; Wed, 29 Jun 2022 22:28:42 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 33544207DF for ; Thu, 30 Jun 2022 02:28:42 +0000 (UTC) X-FDA: 79633318884.03.7ABFF87 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by imf10.hostedemail.com (Postfix) with ESMTP id 9CF79C0037 for ; Thu, 30 Jun 2022 02:28:41 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1656556120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4mMm895HUGvB33w+4B1AJ2mtagQIDtCZZ7dWMv/EeV8=; b=pxOQzK9c3614wZpIA9bTTIlOONEBtlmPH5jhzWmnJd1T0tQkE3B3zB0yTclKMyK9dLA+v/ bwLME081ejMd5Xc+Kys/lGZvLXfzPMxebjdTvUXtI+e0XK6dls/CrW3YkoOdG1HtAUEqC5 yOfSTu9FiikLkQrq1tWumgXTkTDSdP4= From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , David Hildenbrand , Mike Kravetz , Miaohe Lin , Liu Shixin , Yang Shi , Oscar Salvador , Muchun Song , Naoya Horiguchi , linux-kernel@vger.kernel.org Subject: [PATCH v3 8/9] mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage Date: Thu, 30 Jun 2022 11:27:54 +0900 Message-Id: <20220630022755.3362349-9-naoya.horiguchi@linux.dev> In-Reply-To: <20220630022755.3362349-1-naoya.horiguchi@linux.dev> References: <20220630022755.3362349-1-naoya.horiguchi@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1656556122; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4mMm895HUGvB33w+4B1AJ2mtagQIDtCZZ7dWMv/EeV8=; b=dDi5c6WWp34h2tRrz0gcxNY5XTFDKIKzaG4hzzGwpFstjbV5GCz/ODHYDS+2EG10yHHi7D abAiQqFOBdMWc/dlDq43J7JsemcXkrgqSQSAFWTZVex0g/8Ny8ubqAwdeDhXLZxjfmveNK 0lxHLeveAx7ri+rq1crIp9XnECDwJiM= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1656556122; a=rsa-sha256; cv=none; b=VI/2LbEG+fGDGqfVhGJ4+nQVvTfP3Io1EpgjFfH8s1xx8tg7t3qkh6muZkuKFi19qdxcRP 57DIiYtGqbHJ7MgiEC5LObEiaEIEA+kLenddsPNxhseus147DOC+I+E85fyOhvXuERHXlG ivQOSTXxT0Sokoj+QxRO8HUiaCJcLl0= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=pxOQzK9c; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf10.hostedemail.com: domain of naoya.horiguchi@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=naoya.horiguchi@linux.dev Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=pxOQzK9c; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf10.hostedemail.com: domain of naoya.horiguchi@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=naoya.horiguchi@linux.dev X-Rspamd-Server: rspam03 X-Rspam-User: X-Stat-Signature: hkm3obhkt649jqbjxyk4az81be5odycy X-Rspamd-Queue-Id: 9CF79C0037 X-HE-Tag: 1656556121-62529 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: From: Naoya Horiguchi Currently if memory_failure() (modified to remove blocking code with subsequent patch) is called on a page in some 1GB hugepage, memory error handling fails and the raw error page gets into leaked state. The impact is small in production systems (just leaked single 4kB page), but this limits the testability because unpoison doesn't work for it. We can no longer create 1GB hugepage on the 1GB physical address range with such leaked pages, that's not useful when testing on small systems. When a hwpoison page in a 1GB hugepage is handled, it's caught by the PageHWPoison check in free_pages_prepare() because the 1GB hugepage is broken down into raw error pages before coming to this point: if (unlikely(PageHWPoison(page)) && !order) { ... return false; } Then, the page is not sent to buddy and the page refcount is left 0. Originally this check is supposed to work when the error page is freed from page_handle_poison() (that is called from soft-offline), but now we are opening another path to call it, so the callers of __page_handle_poison() need to handle the case by considering the return value 0 as success. Then page refcount for hwpoison is properly incremented so unpoison works. Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin --- v2 -> v3: - remove "res = MF_FAILED" in try_memory_failure_hugetlb (by Miaohe) --- mm/memory-failure.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 6c7b9129eade..6a9b11807ee6 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1046,7 +1046,6 @@ static int me_huge_page(struct page_state *ps, struct page *p) res = truncate_error_page(hpage, page_to_pfn(p), mapping); unlock_page(hpage); } else { - res = MF_FAILED; unlock_page(hpage); /* * migration entry prevents later access on error hugepage, @@ -1054,9 +1053,11 @@ static int me_huge_page(struct page_state *ps, struct page *p) * subpages. */ put_page(hpage); - if (__page_handle_poison(p) > 0) { + if (__page_handle_poison(p) >= 0) { page_ref_inc(p); res = MF_RECOVERED; + } else { + res = MF_FAILED; } } @@ -1689,10 +1690,11 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb */ if (res == 0) { unlock_page(head); - res = MF_FAILED; - if (__page_handle_poison(p) > 0) { + if (__page_handle_poison(p) >= 0) { page_ref_inc(p); res = MF_RECOVERED; + } else { + res = MF_FAILED; } action_result(pfn, MF_MSG_FREE_HUGE, res); return res == MF_RECOVERED ? 0 : -EBUSY; -- 2.25.1