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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE, SPF_PASS,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 EF5E9C433EC for ; Tue, 30 Mar 2021 21:28:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9CFE619D6 for ; Tue, 30 Mar 2021 21:28:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233041AbhC3V2E (ORCPT ); Tue, 30 Mar 2021 17:28:04 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:49990 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232634AbhC3V1S (ORCPT ); Tue, 30 Mar 2021 17:27:18 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 12ULNipW130302; Tue, 30 Mar 2021 21:26:26 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-type : mime-version; s=corp-2020-01-29; bh=yDLRLnFTPQdctAMZcnaA/yaqg3MDXIWikseBX1dUNEY=; b=DgsQHnDDCS6pEshRFyMtvkwK3Wa0oBdlzobJFg1w+FCLaMY5brkw4jeaXwAA+b0n+Ew1 Oc/GDsy2U3G0FEkHcI7O9GEALMEN06cQfZak8HgrxSIdOKXDVLYAqEv68nOkLZpvPe2v 6dqg/TnLPC8gtWnP4WW762EbnB5u0gVSVO34idsfQLSy9mKLV1ix7ZUlkNIk9be/cxnx MJoVI8wpvok0a2pJHAPNJnt3SWi0a2OO0T0l7nvVbbiOm9j1QFgvCcuSaeNV8XSrIFRl JbLEfiLJ/HlAEdu5A50dBlVlX34qirLur2pOCiSsn0AFs94Hw8H31ygoy8OTlx6eOM2T Sg== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 37mabqr8p6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Mar 2021 21:26:26 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 12ULOnOa184080; Tue, 30 Mar 2021 21:26:26 GMT Received: from nam10-mw2-obe.outbound.protection.outlook.com (mail-mw2nam10lp2106.outbound.protection.outlook.com [104.47.55.106]) by aserp3020.oracle.com with ESMTP id 37mac7u4jc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Mar 2021 21:26:26 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=F9aIyh+rzc8JG5NcLpgVyBk0+dmxAkmNEidhBIFjLAIiyNiPj0xTGplcPM6Z8rDFLCnCP0zbELWP1zdiuWCLyiPt+gJ9YIVT7EZzG/hFFX6kNJevQ6fNZujn33DyJJmGh1TeTCePQpwNtzTzLG1JBk/W7pe1gYbjr0RZnk7T/7Bj8PylmMZbfOetHtxQUd7dA/pyROrUXihIaeoeIpbRxYair54yr6or0Kc75yeD4efbwUehMNcw1pMXBw80Pxue8CH7rgmSIdqjEBOeSswbkoi6UoaoXaphJXMMEh85DoS4cFm7cTy6WRqXq8J/wWMdZjhvMVC2Xp0p2zIQVOh6Ng== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=yDLRLnFTPQdctAMZcnaA/yaqg3MDXIWikseBX1dUNEY=; b=NokgA0AwQQZPdYMsVQIYdI7pCYtRTKH/qP6zq2mt+tL7yP44dGiIID4Et+zpg0RVAztycob6b9Dw2ocf7DXKEuz7LFp/tjRgsZgrlrEPRbXKF/qdkf7lcssXACu6kZ7eA3f+cvG2GxhJFCnkpZqDsHzNuC0z73O5onN2bPH4ZntZ0BQiK/sVisf2ZpCf0dJweooctxpFgHgxUOyj9xALalzyPZHxPJdLVnAn2kx6E+RtX1tURHouqBDkLU/yKK4TqPwRQUjdSmU/6FXyQYKN1Fy9nUqfT0ozCDRCZTjwbhFlc6+EUoZcJHSoUQaHfhGOS2TcH9AJITeQHeAGZj2wMQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=yDLRLnFTPQdctAMZcnaA/yaqg3MDXIWikseBX1dUNEY=; b=cpiWQRYER8WlZKIptvBBW5ajuylUdnkkiNfuAytYDCYNNpgtQoehPy3klXpMtgM1CkIgmD+4vDZB3hhC1C8EgveS7bFunDe96+F5iH34tlqJdj85CVxX+gTwZcZLCujwXpjKb586bwosxnnUTt0ht1fhMtWfcXjdw+ZYNexi9qs= Authentication-Results: kvack.org; dkim=none (message not signed) header.d=none;kvack.org; dmarc=none action=none header.from=oracle.com; Received: from MN2PR10MB3533.namprd10.prod.outlook.com (2603:10b6:208:118::32) by MN2PR10MB3600.namprd10.prod.outlook.com (2603:10b6:208:114::29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3977.24; Tue, 30 Mar 2021 21:26:22 +0000 Received: from MN2PR10MB3533.namprd10.prod.outlook.com ([fe80::cc79:c40e:430f:e254]) by MN2PR10MB3533.namprd10.prod.outlook.com ([fe80::cc79:c40e:430f:e254%4]) with mapi id 15.20.3977.033; Tue, 30 Mar 2021 21:26:22 +0000 From: Anthony Yznaga To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: willy@infradead.org, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, hughd@google.com, ebiederm@xmission.com, keescook@chromium.org, ardb@kernel.org, nivedita@alum.mit.edu, jroedel@suse.de, masahiroy@kernel.org, nathan@kernel.org, terrelln@fb.com, vincenzo.frascino@arm.com, martin.b.radev@gmail.com, andreyknvl@google.com, daniel.kiper@oracle.com, rafael.j.wysocki@intel.com, dan.j.williams@intel.com, Jonathan.Cameron@huawei.com, bhe@redhat.com, rminnich@gmail.com, ashish.kalra@amd.com, guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz, alex.shi@linux.alibaba.com, david@redhat.com, richard.weiyang@gmail.com, vdavydov.dev@gmail.com, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, daniel.m.jordan@oracle.com, steven.sistare@oracle.com, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org Subject: [RFC v2 19/43] mm: PKRAM: allow preserved memory to be freed from userspace Date: Tue, 30 Mar 2021 14:35:54 -0700 Message-Id: <1617140178-8773-20-git-send-email-anthony.yznaga@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1617140178-8773-1-git-send-email-anthony.yznaga@oracle.com> References: <1617140178-8773-1-git-send-email-anthony.yznaga@oracle.com> Content-Type: text/plain X-Originating-IP: [148.87.23.8] X-ClientProxiedBy: BYAPR11CA0099.namprd11.prod.outlook.com (2603:10b6:a03:f4::40) To MN2PR10MB3533.namprd10.prod.outlook.com (2603:10b6:208:118::32) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from ca-qasparc-x86-2.us.oracle.com (148.87.23.8) by BYAPR11CA0099.namprd11.prod.outlook.com (2603:10b6:a03:f4::40) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3977.26 via Frontend Transport; Tue, 30 Mar 2021 21:26:17 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: e0fe7fd5-ae02-4534-9153-08d8f3c276f7 X-MS-TrafficTypeDiagnostic: MN2PR10MB3600: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:1284; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MN2PR10MB3533.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(376002)(136003)(346002)(366004)(39860400002)(396003)(6666004)(7696005)(316002)(36756003)(44832011)(8936002)(2616005)(956004)(5660300002)(16526019)(186003)(4326008)(6486002)(86362001)(38100700001)(83380400001)(26005)(66476007)(7406005)(7416002)(66556008)(8676002)(478600001)(52116002)(2906002)(66946007);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?zGgcDEKHqfeVCT6VOZzkY6o7Q/fGlOllFxgjhXVxYC/1UsKgvTjjTR/d1Ylm?= =?us-ascii?Q?ezhecaPUG3qGttqpq1Ty9yQCSaMPyHFX1soNRESq5DCim+r52YmKQy30ZhIF?= =?us-ascii?Q?qS0EnoX9MnuO0cz+lApazd6tubMLHLqs8ZEozAo7584lpWyy5PqJWIi9eaPo?= =?us-ascii?Q?0U/mmGbegw8rT1rS8rXrMpXzqm9HA0B9T1YsS77RL4u6xh/XybYUd5p9MUCq?= =?us-ascii?Q?PsU/5jJxceBbjfeCG0/bbE/2iEw1CK153wfl4r9aGVjq89u88BdR+H8Z688C?= =?us-ascii?Q?a7j6CJZ1KvlrCmNf4F5b+7DzYX64Um34HG1l4SEX5W1fiOgTiMZPjmnEhreo?= =?us-ascii?Q?i4VEOG2kEj5SWWmOODKh4YyWfGCQTag+zHmcdPXyI0rgk/FloyzzIsFpmgoL?= =?us-ascii?Q?FLp3nze4xrNMUvGE31pCOumGEmMyHkyNCcF5XRnlGilXeuVtqQSr57VCmIU0?= =?us-ascii?Q?vof5O/6+h/7bx9PFdy9QXWPL6sxeFdQXp1f4WPZxsiJouM3EEUSdnVRjvskF?= =?us-ascii?Q?dp6MfaYWrogUaNd5RdgguAHrUzlF2aZjOGfHkixZft/PBZFpfTNVzDKxGuva?= =?us-ascii?Q?cxyEIdMKQZGpjrOKp9LMutjn2kZz8yLi2xpgl6sXKpXyEcCmLXuh0MUkbSZZ?= =?us-ascii?Q?L04yBDv3i+xVLuMjyveycI4WsSUwnkVaBBHX/UjjaZbUIiWwMsW8bz129ASS?= =?us-ascii?Q?hWiSCnNPOxhe7VxR8DC7xT+gr+mD6HagljJrImhyEO5wL51dWn84RjDnkKnj?= =?us-ascii?Q?UCrF414MtT7eHpNbZ5Rbmhbd7ZhPpEIV8D/IJdR+Ip3OGMLK/ZF+hQrTA1AE?= =?us-ascii?Q?9MTkNJ2T9NpmTdezWHyN1TYjeoQbX0cawAJOLhqesxcwAiUMGpJpyyil+cKy?= =?us-ascii?Q?RblrV71yVMuO+awQYGheBDSvGJuwOGpMO+8PwIkPDbyzU1Ewg0UKS5POpab4?= =?us-ascii?Q?3Z5B0v9p2YiSGmPL9T6Kgypl9+aUNPLR9Gj30aqAcMidSDGhXHpXMJn9KQmD?= =?us-ascii?Q?GBOBBvrBUfC7TXGDzGNAi0W86lHhyedNEiiHDX9sJ2e3jVNy7ughbmBKpV+t?= =?us-ascii?Q?YxFdvIEHP6dJl8nf6dDvCTzCcmWFVKLcEDkOG5wChojzx0uid1JcbLihdDxG?= =?us-ascii?Q?/vGfR/Bzvy+NxsDB/4wbfgdtwbIlMSOke8EVMtyg4bPevP7+lmLMMo7ENXQ0?= =?us-ascii?Q?0Wqm4RWfiCTHpT2yV4H28t/BHGnafQIOV358WkMK/w957Rn+Bxs94F3gFJM5?= =?us-ascii?Q?1JOVJ+S5KmDHGLUFIfHbZNJp56kBQUof5GPFKX8dToECca0NqpKvE9XZAqRp?= =?us-ascii?Q?JxFJR5guZPuLJszhY3qcdIRp?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: e0fe7fd5-ae02-4534-9153-08d8f3c276f7 X-MS-Exchange-CrossTenant-AuthSource: MN2PR10MB3533.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Mar 2021 21:26:21.9715 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: TjI0o54wg1wET4H4pvLmJOFxn9DvnTgp++5XWTRmE/7EHsrdO/He/08Z3hnGMUYO54Bd6PAmaC4mY0LgnDHmId/vxePsT3oAz7DXLwMJeV8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR10MB3600 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9939 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 mlxscore=0 adultscore=0 spamscore=0 malwarescore=0 phishscore=0 suspectscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2103300000 definitions=main-2103300156 X-Proofpoint-ORIG-GUID: pMc0HMVeS0xDmcIluKiakYKWipZMKCXj X-Proofpoint-GUID: pMc0HMVeS0xDmcIluKiakYKWipZMKCXj X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9939 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 impostorscore=0 priorityscore=1501 lowpriorityscore=0 malwarescore=0 suspectscore=0 adultscore=0 mlxscore=0 bulkscore=0 spamscore=0 clxscore=1015 mlxlogscore=999 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2103300000 definitions=main-2103300156 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To free all space utilized for preserved memory, one can write 0 to /sys/kernel/pkram. This will destroy all PKRAM nodes that are not currently being read or written. Originally-by: Vladimir Davydov Signed-off-by: Anthony Yznaga --- mm/pkram.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/mm/pkram.c b/mm/pkram.c index dcf84ba785a7..8700fd77dc67 100644 --- a/mm/pkram.c +++ b/mm/pkram.c @@ -493,6 +493,32 @@ static void pkram_truncate_node(struct pkram_node *node) node->obj_pfn = 0; } +/* + * Free all nodes that are not under operation. + */ +static void pkram_truncate(void) +{ + struct page *page, *tmp; + struct pkram_node *node; + LIST_HEAD(dispose); + + mutex_lock(&pkram_mutex); + list_for_each_entry_safe(page, tmp, &pkram_nodes, lru) { + node = page_address(page); + if (!(node->flags & PKRAM_ACCMODE_MASK)) + list_move(&page->lru, &dispose); + } + mutex_unlock(&pkram_mutex); + + while (!list_empty(&dispose)) { + page = list_first_entry(&dispose, struct page, lru); + list_del(&page->lru); + node = page_address(page); + pkram_truncate_node(node); + pkram_free_page(node); + } +} + static void pkram_add_link(struct pkram_link *link, struct pkram_data_stream *pds) { __u64 link_pfn = page_to_pfn(virt_to_page(link)); @@ -1233,8 +1259,19 @@ static ssize_t show_pkram_sb_pfn(struct kobject *kobj, return sprintf(buf, "%lx\n", pfn); } +static ssize_t store_pkram_sb_pfn(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, size_t count) +{ + int val; + + if (kstrtoint(buf, 0, &val) || val) + return -EINVAL; + pkram_truncate(); + return count; +} + static struct kobj_attribute pkram_sb_pfn_attr = - __ATTR(pkram, 0444, show_pkram_sb_pfn, NULL); + __ATTR(pkram, 0644, show_pkram_sb_pfn, store_pkram_sb_pfn); static struct attribute *pkram_attrs[] = { &pkram_sb_pfn_attr.attr, -- 1.8.3.1