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 6BF15FA373D for ; Fri, 28 Oct 2022 02:28:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EDE5B6B0072; Thu, 27 Oct 2022 22:28:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E8ECB6B0073; Thu, 27 Oct 2022 22:28:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D2F1D6B0074; Thu, 27 Oct 2022 22:28:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C0E056B0072 for ; Thu, 27 Oct 2022 22:28:53 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 8EAFAABB15 for ; Fri, 28 Oct 2022 02:28:53 +0000 (UTC) X-FDA: 80068775346.28.19464C9 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by imf10.hostedemail.com (Postfix) with ESMTP id CF3B7C0003 for ; Fri, 28 Oct 2022 02:28:50 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Mz5vV674vz15MG0; Fri, 28 Oct 2022 10:23:50 +0800 (CST) Received: from [10.174.151.185] (10.174.151.185) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 28 Oct 2022 10:28:45 +0800 Subject: Re: [PATCH v3 2/2] mm, hwpoison: When copy-on-write hits poison, take page offline To: Tony Luck CC: Matthew Wilcox , Shuai Xue , Dan Williams , Michael Ellerman , Nicholas Piggin , Christophe Leroy , , , , Naoya Horiguchi , Andrew Morton References: <20221019170835.155381-1-tony.luck@intel.com> <20221021200120.175753-1-tony.luck@intel.com> <20221021200120.175753-3-tony.luck@intel.com> From: Miaohe Lin Message-ID: Date: Fri, 28 Oct 2022 10:28:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20221021200120.175753-3-tony.luck@intel.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.151.185] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666924131; a=rsa-sha256; cv=none; b=q9yYC5K1LIwNxqbW+wUy/dipbWZoXwIjmaq6cc820fQreByAuQ2YDO2tsChRcGLRAN+aFj +HrwiOrmAmxVY+whaaFf69WkmetDi20t85K/bpH/rQWnVCCecHMUULwL0AQzm4jJpUHQSi XE8CMEUzzyyxzXOXp0FKNuYs2qvu/lQ= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf10.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666924131; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rvpW+cHUuWnmHuM/EJFbvTvYtUum6wuDl0XWcgh41o4=; b=X4wOeydt401QqYW8dvPIu/X9U/BL+I8wKbGPQbcN0NYmUFnVg7nWQEAx/aVVSwmrd2WCmE TOAY5NlQxlwIt5ws+98gUc837FidtrNL64ezK6IvFcZG+R1dZd+tUsXE5iXvAv2B9uZVw1 rr6vSwAV8rgECKqc25iDGykA1wLDObw= X-Stat-Signature: 9paacjnhbb97ccy98888wadec5b5yedt X-Rspamd-Queue-Id: CF3B7C0003 X-Rspam-User: Authentication-Results: imf10.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf10.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspamd-Server: rspam09 X-HE-Tag: 1666924130-953820 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: On 2022/10/22 4:01, Tony Luck wrote: > Cannot call memory_failure() directly from the fault handler because > mmap_lock (and others) are held. Could you please explain which lock makes it unfeasible to call memory_failure() directly and why? I'm somewhat confused. But I agree using memory_failure_queue() should be a good idea. > > It is important, but not urgent, to mark the source page as h/w poisoned > and unmap it from other tasks. > > Use memory_failure_queue() to request a call to memory_failure() for the > page with the error. > > Also provide a stub version for CONFIG_MEMORY_FAILURE=n > > Signed-off-by: Tony Luck > --- > include/linux/mm.h | 5 ++++- > mm/memory.c | 4 +++- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 8bbcccbc5565..03ced659eb58 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3268,7 +3268,6 @@ enum mf_flags { > int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, > unsigned long count, int mf_flags); > extern int memory_failure(unsigned long pfn, int flags); > -extern void memory_failure_queue(unsigned long pfn, int flags); > extern void memory_failure_queue_kick(int cpu); > extern int unpoison_memory(unsigned long pfn); > extern int sysctl_memory_failure_early_kill; > @@ -3277,8 +3276,12 @@ extern void shake_page(struct page *p); > extern atomic_long_t num_poisoned_pages __read_mostly; > extern int soft_offline_page(unsigned long pfn, int flags); > #ifdef CONFIG_MEMORY_FAILURE > +extern void memory_failure_queue(unsigned long pfn, int flags); > extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags); > #else > +static inline void memory_failure_queue(unsigned long pfn, int flags) > +{ > +} > static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) > { > return 0; > diff --git a/mm/memory.c b/mm/memory.c > index b6056eef2f72..eae242351726 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2866,8 +2866,10 @@ static inline int __wp_page_copy_user(struct page *dst, struct page *src, > unsigned long addr = vmf->address; > > if (likely(src)) { > - if (copy_mc_user_highpage(dst, src, addr, vma)) > + if (copy_mc_user_highpage(dst, src, addr, vma)) { > + memory_failure_queue(page_to_pfn(src), 0); It seems MF_ACTION_REQUIRED is not needed for memory_failure_queue() here. Thanks for your patch. Reviewed-by: Miaohe Lin Thanks, Miaohe Lin