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 3BA11FA3741 for ; Sat, 29 Oct 2022 02:49:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8EDAD6B0072; Fri, 28 Oct 2022 22:49:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 89DA96B0073; Fri, 28 Oct 2022 22:49:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78C666B0074; Fri, 28 Oct 2022 22:49:18 -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 68C386B0072 for ; Fri, 28 Oct 2022 22:49:18 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 3F8AEA05FE for ; Sat, 29 Oct 2022 02:49:18 +0000 (UTC) X-FDA: 80072455596.14.2C71790 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by imf13.hostedemail.com (Postfix) with ESMTP id 48DAB20009 for ; Sat, 29 Oct 2022 02:49:15 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4MzkJc01cGz15MF4; Sat, 29 Oct 2022 10:44:15 +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; Sat, 29 Oct 2022 10:49:11 +0800 Subject: Re: [PATCH RFC 2/2] mm: Use pte markers for swap errors To: Peter Xu , , CC: Huang Ying , Andrew Morton , HORIGUCHI NAOYA , David Hildenbrand , Andrea Arcangeli References: <20221024204830.1342169-1-peterx@redhat.com> <20221024204830.1342169-3-peterx@redhat.com> From: Miaohe Lin Message-ID: <6357f4ab-32f1-3654-9a18-deb4f5364a92@huawei.com> Date: Sat, 29 Oct 2022 10:49:11 +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: <20221024204830.1342169-3-peterx@redhat.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: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667011758; a=rsa-sha256; cv=none; b=ChMhCDdhg44gwAMEsDJNjUM4cCGzSNQCUH9C/ql1ODhbgU/dh3gkPHwoqW/MbKoQIOWFbG X2HNIrc+SSIpfIL8sRhvKiTPTQhn31XkqSOjyvQiD0sBU8Yt1F0USd0W0YR3yUU/etFJ1O LvhI0H6COmcYAl3e1JCh+6epHKmavQw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667011758; 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=Wtv1tHCMcjCucF9EcAsdtrO/oOR80sXvrvPydUMC0vM=; b=xLMTFuQQjsVtZJq5tGacWD8SD0ZRWdFaquIh6C6l4sm7AKmoCXEejGYA/Fh4YQwdrqqHuo mLioTUqS94/34Lr5NRKzS6+GzOKfp3F5hp5NvBG9C1Nz/5putNXgVu8lih02usM92AQmmK 5XnoSw0j0fhZ+MZlzXg0RKevfaqeuS4= X-Rspam-User: Authentication-Results: imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam07 X-Stat-Signature: guixfktx8zeas1ef5agmcujbb5x4ajp7 X-Rspamd-Queue-Id: 48DAB20009 X-HE-Tag: 1667011755-897303 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 2022/10/25 4:48, Peter Xu wrote: > PTE markers are ideal mechanism for things like SWP_SWAPIN_ERROR. Using a > whole swap entry type for this purpose can be an overkill, especially if we > already have PTE markers. Define a new bit for swapin error and replace it > with pte markers. Then we can safely drop SWP_SWAPIN_ERROR and give one > device slot back to swap. > > We used to have SWP_SWAPIN_ERROR taking the page pfn as part of the swap > entry, but it's never used. Neither do I see how it can be useful because > normally the swapin failure should not be caused by a bad page but bad swap > device. Drop it alongside. > > Signed-off-by: Peter Xu Thanks for doing this. I have been waiting this for a "long" time. ;) With changing the name of PTE_MARKER_SWAP_ERROR proposed by David, this patch looks good to me. Reviewed-by: Miaohe Lin Thanks, Miaohe Lin