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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: uJx1kFDFTaxAAHYsJdXaeiWg8CWTEVAOx4SDBbInHeRci1FsyxR3crqJ8az5F6YmWY67t5dirW3Ipu1amW9jR4mZ68fZ8BdXp77QIgwL216D8XmPlaiI16rmjCCxUXiWtnHOCoO3In4vUAPc/OhR3BlfpTxJYtSvhitLjiqzX65BHPiBcRs5V5uKAwfLTCi/MvUSV9zRjhyeMRTaRxHGK2F1BHE+UYdqOyVmTluDIkdbv+lVf/Kwi9afq2hlqRkEGfQb+Z/CYb6DJn6usplIWPn7Nak673E51yj7w4cP4ZJnx7H6UGyyLf9G7nFDiG17hye1ljo8XcFvEZcHQK2IMIxMrI0PnQRN3xs/bFEFsf3M/3a1EXEnj8S3ShZtgibdiy0JpIuoQjNZt/7enj9S96agmkek+nvkMeAahlO85ulfeXWlr78wbDQHCW0qT1Zg X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Sep 2026 05:22:13.4777 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 65e6754b-27b8-4c57-74c0-08df147ba1ac 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=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SJ5PEPF000001D0.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB6975 Hello John, On 9/16/2026 11:27 PM, John Stultz wrote: > On Tue, Sep 15, 2026 at 10:22 PM John Stultz wrote: >> The series definitely looks interesting, and it seems to be holding up >> ok in testing. Though figuring out how to refactor them so that they > > Well, I did hit the following last night during stress testing: > > [11176.672951] WARNING: kernel/sched/sched.h:1645 at > sched_change_begin+0x1b6/0x2b0, CPU#14: torture_shuffle/433 > [11176.676650] CPU: 14 UID: 0 PID: 433 Comm: torture_shuffle Not > tainted 7.2.0-rc4-00032-gf14e36dcc837-dirty #138 PREEMPT(full) > [11176.680917] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS 1.17.0-debian-1.17.0-1 04/01/2014 > [11176.684794] RIP: 0010:sched_change_begin+0x1b6/0x2b0 > [11176.686748] Code: c9 1e 48 89 03 80 7b 1c 00 0f 85 ca 00 00 00 80 > 7b 1d 00 0f 85 91 00 00 00 48 89 d8 5b 5d 41 5c 41 5d 41 5e e9 1b 63 > 23 01 90 <0f> 0b 90 41 f6 c5 08 0f 85 c7 fe ff ff 48 89 ef 41 83 cd 08 > e8 b1 > [11176.693913] RSP: 0018:ffffc900010b3e10 EFLAGS: 00010046 > [11176.695962] RAX: 0000000000000000 RBX: ffff8881b9198020 RCX: 0000000000000001 > [11176.698747] RDX: 0000000000000001 RSI: ffffffff82c8b519 RDI: ffffffff82cad7fe > [11176.701554] RBP: ffff8881b91abdc0 R08: 0000000000000001 R09: 00000000d19ffe29 > [11176.704561] R10: 000000000000000e R11: ffff88810264cff0 R12: ffff888106694400 > [11176.707423] R13: 0000000000000002 R14: 0000000000000000 R15: ffffc90000017d58 > [11176.710161] FS: 0000000000000000(0000) GS:ffff88823563e000(0000) > knlGS:0000000000000000 > [11176.713196] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [11176.715628] CR2: 0000000000000000 CR3: 00000001072a7006 CR4: 0000000000370ef0 > [11176.718462] Call Trace: > [11176.719460] > [11176.720319] __set_cpus_allowed_ptr_locked+0x146/0x1f0 > [11176.722343] ? __pfx_torture_shuffle+0x10/0x10 > [11176.724063] __set_cpus_allowed_ptr+0x64/0xa0 > [11176.725913] set_cpus_allowed_ptr+0x3a/0x60 > [11176.727513] torture_shuffle+0x12b/0x230 > [11176.729014] kthread+0x103/0x130 > [11176.730304] ? __pfx_kthread+0x10/0x10 > [11176.731758] ret_from_fork+0x27c/0x340 > [11176.733220] ? __pfx_kthread+0x10/0x10 > [11176.734680] ret_from_fork_asm+0x1a/0x30 > [11176.736366] > > Followed shortly after by: > [11663.223681] kernel BUG at kernel/sched/rt.c:1020! > [11663.226093] Oops: invalid opcode: 0000 [#1] SMP NOPTI > [11663.228669] CPU: 46 UID: 0 PID: 0 Comm: swapper/46 Tainted: G > W 7.2.0-rc4-00032-gf14e36dcc837-dirty #138 PREEMPT(full) > [11663.234796] Tainted: [W]=WARN > [11663.236392] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS 1.17.0-debian-1.17.0-1 04/01/2014 > [11663.241196] RIP: 0010:dequeue_rt_stack+0x2ad/0x2c0 > [11663.243652] Code: 83 a8 fe ff ff 39 c1 0f 8e 47 ff ff ff 90 0f 0b > 90 e9 b7 fd ff ff 90 0f 0b 90 e9 e8 fd ff ff f3 48 0f bc d0 e9 80 fe > ff ff 90 <0f> 0b 48 8d 3d 1a 79 dc 01 67 48 0f b9 3a e9 e9 fe ff ff 90 > 90 90 > [11663.253981] RSP: 0018:ffffc90000c10dd8 EFLAGS: 00010046 > [11663.256630] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88810ad50080 > [11663.260225] RDX: ffff888235e3e000 RSI: 0000000000000000 RDI: ffff88810ad501c0 > [11663.263862] RBP: ffff8881b99abdc0 R08: 0000000000000000 R09: ffffffff83b9a280 > [11663.266876] R10: 000000000000002e R11: 0000000000000000 R12: ffff8881b99abdc0 > [11663.269626] R13: ffff88810ad501c0 R14: 0000000000000000 R15: 0000000000000025 > [11663.272412] FS: 0000000000000000(0000) GS:ffff888235e3e000(0000) > knlGS:0000000000000000 > [11663.276347] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [11663.279185] CR2: 00007f03955d60ac CR3: 00000001072a7006 CR4: 0000000000370ef0 > [11663.282698] Call Trace: > [11663.284061] > [11663.285116] enqueue_task_rt+0x77/0x3f0 > [11663.287276] enqueue_task+0x1cf/0x330 > [11663.289121] proxy_activate_blocked_task+0x498/0x640 > [11663.291579] ttwu_do_activate+0x287/0x290 > [11663.293582] sched_ttwu_pending+0x10b/0x220 > [11663.295726] __flush_smp_call_function_queue+0x1f8/0x680 > [11663.298320] __sysvec_call_function_single+0x35/0x180 > [11663.300877] sysvec_call_function_single+0x8a/0xb0 > [11663.303287] > [11663.304376] > [11663.305467] asm_sysvec_call_function_single+0x1a/0x20 > [11663.307994] RIP: 0010:pv_native_safe_halt+0xf/0x20 > > > The only change I made to your tree was passing the rf into > proxy_activate_blocked_task, to use rq_(un)lock() instead of > raw_spin_rq_(un)lock(). Thank you for testing and the report! Let me go find what I've broken. -- Thanks and Regards, Prateek