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Miller" , Andreas Larsson , Thomas Gleixner , Borislav Petkov , Dave Hansen , References: <20261001192849.74788-1-kprateek.nayak@amd.com> <20261001192849.74788-2-kprateek.nayak@amd.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1PEPF000066ED:EE_|DS2PR12MB9797:EE_ X-MS-Office365-Filtering-Correlation-Id: 5b0a118a-34f1-4874-96e7-08df2806312d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|82310400026|36860700016|1800799024|23010399003|4143699003|11063799006|56012099006|18002099003|22082099003|261009223027099003|10067099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb08.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(7416014)(82310400026)(36860700016)(1800799024)(23010399003)(4143699003)(11063799006)(56012099006)(18002099003)(22082099003)(261009223027099003)(10067099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: u8cudUGIMWd1kdY446WXLGgLVLJBygI3oVZ4GGvHL2xooEZ7RpwVnK67ZiYHo16oFsrUqQUeEYqd2hgReUWwMhuSOK6Pi/pRcWofXkHZZKWTRl8/OLbMmQPzGIfKhouUZHVI0ryZe8S2XsfRW18hsplbSN8BRRngxvOUKG2VX6jIKbE5d7/+ybybmtFjXkHuvG2XmxVNKkmaLjEa+pfiXwXKcmyqPHX+Vd9PNNYtX2nTpcd4A1rz4r9wyhMSDsLaxPZ4GKF7KZ4whtAVfmTBCdUr9/ak35n8i0/hRwbKMaXBy6Qq++460It8XPFBkuBDTOddkRwxTiJuwUE9dcfb/15XaIILggWiGcTF1ovwEGG2CqsNAu6nntu+ap67zFhsJhCc5gPT999YrvGTTajGhKyP55BV60ETzacT7Jaobhs+CsBUnQ5kYNYPJISSeUa8 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Oct 2026 02:11:56.8563 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5b0a118a-34f1-4874-96e7-08df2806312d X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CO1PEPF000066ED.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS2PR12MB9797 Hello Shrikanth, On 10/7/2026 11:13 AM, Shrikanth Hegde wrote: > Hi Prateek. > > I ran the series on 320 CPU power11 system today. > hackbench shows high regression across the different number of groups and > it is more severe at lower number of groups. I haven't run anything else yet. > > I haven't taken a look at the patches yet. Post your talk today will try to > go through and see if i can spot something. Thanks a ton for the testing. Now that I'm back, I'll take a look at few bits again, especially stuff for optimizing traversals. Can you please share what does your system topology look like and what did: sudo dmesg | grep sbm say when you booted into your kernel? >> +void __init sbm_set_topology(int num_instances, int max_threads_per_instance) >> +{ >> +    sbm_max_threads_per_instance = max_threads_per_instance; >> +    sbm_num_instance = num_instances; >> + >> +    pr_info("sbm topology set to %d instance(s) with a maximum of %d thread(s) per instance\n", >> +        sbm_num_instance, >> +        sbm_max_threads_per_instance); >> +} > > nit: Stray empty line at the end. Ack! Thank you again for taking a look. > >> + -- Thanks and Regards, Prateek