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linux-cxl@vger.kernel.org, osalvador@suse.de, gregkh@linuxfoundation.org, rafael@kernel.org, djakov@kernel.org Subject: Re: [PATCH v2] drivers/base/memory: set mem->altmap after successful device registration Message-ID: References: <20260514092657.3057141-1-georgi.djakov@oss.qualcomm.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260514092657.3057141-1-georgi.djakov@oss.qualcomm.com> X-ClientProxiedBy: KU0P306CA0084.MYSP306.PROD.OUTLOOK.COM (2603:1096:d10:2b::9) To BL0PR12MB2370.namprd12.prod.outlook.com (2603:10b6:207:47::27) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL0PR12MB2370:EE_|PH7PR12MB7378:EE_ X-MS-Office365-Filtering-Correlation-Id: c4fb2c76-3045-461a-6ce8-08deb1a0c5d3 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|1800799024|18002099003|22082099003|56012099003|11063799003; X-Microsoft-Antispam-Message-Info: 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This was triggered by modifying virtio-mem > driver. > I see you mentioned about some out of tree virtio_mem patches that can trigger the bug, mind to paste the tree link here ? Just curious. Best regards, Richard Cheng. > Fix this by delaying the assignment of mem->altmap until after > __add_memory_block() has succeeded. > > Fixes: 1a8c64e11043 ("mm/memory_hotplug: embed vmem_altmap details in memory block") > Signed-off-by: Georgi Djakov > --- > > v1: https://patch.msgid.link/20260513130900.2204499-1-georgi.djakov@oss.qualcomm.com > > drivers/base/memory.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index 11d57cfa8d72..78e9600e6d45 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -807,7 +807,6 @@ static int add_memory_block(unsigned long block_id, int nid, unsigned long state > mem->start_section_nr = block_id * sections_per_block; > mem->state = state; > mem->nid = nid; > - mem->altmap = altmap; > INIT_LIST_HEAD(&mem->group_next); > > #ifndef CONFIG_NUMA > @@ -825,6 +824,8 @@ static int add_memory_block(unsigned long block_id, int nid, unsigned long state > if (ret) > return ret; > > + mem->altmap = altmap; > + > if (group) { > mem->group = group; > list_add(&mem->group_next, &group->memory_blocks); >