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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: QAtzM47XfZpd7ePAfYC3lYxRUHnk+X3QSlIEVOmZ9xlGXrWO2+6SsALaOn0n3dVdJWjhDQOtnCTgaMsdxbGrx1/Qpdp6e+vGbhEJPdbOW7HFq+PFfpYb2divTKXVtjGHW8xBH5pqT5o6vRmzK9xvXrx6xR/GIhO23yXYMN2gwZXLsP/E7Gy9hGJ11w0ojSG49SUOb5R4ULbBvc6WshEENAMXHilLuVduEMwUAtgIX1OFqoSjNIfVN/+C+EO4FHnNHruIzdyRbcmrJsZ7iQ9Ku/q9udtJ9AdzAQL6jgKHt+WzbuJM7ariKJ51gxyeYfuluKMzc+R3lZJ4X9HWUMz8lbIkClOohNVq9jFvFnUBPx4QItfvq4vOQffvev3maaTenYcgY2FXvTUtJYWzoW9tz9I/i1zsgWwnTcdaFzkRIh6BeRGgrHtn25lvHM2f2PLe X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Mar 2026 03:36:49.9165 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: ba6ef0bc-e307-463d-87ed-08de86fb162a 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: CO1PEPF000075F4.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW6PR12MB9018 Hello Nathan, Thank you for the report. On 3/21/2026 5:28 AM, Nathan Chancellor wrote: > $ cat kernel/configs/schedstats.config > CONFIG_SCHEDSTATS=y Is the "schedstats.config" available somewhere? I tried these steps on my end but couldn't reproduce the crash with my config. Also, are you saying it is necessary to enable CONFIG_SCHEDSTATS to observe the crash? > > $ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- mrproper defconfig schedstats.config zImage > > $ curl -LSs https://github.com/ClangBuiltLinux/boot-utils/releases/download/20241120-044434/arm-rootfs.cpio.zst | zstd -d >rootfs.cpio > > $ qemu-system-arm \ > -display none \ > -nodefaults \ > -no-reboot \ > -machine virt \ > -append 'console=ttyAMA0 earlycon' \ > -kernel arch/arm/boot/zImage \ > -initrd rootfs.cpio \ > -m 1G \ > -serial mon:stdio > [ 0.000000] Booting Linux on physical CPU 0x0 > [ 0.000000] Linux version 7.0.0-rc4-00017-g8e8e23dea43e (nathan@framework-amd-ryzen-maxplus-395) (arm-linux-gnueabi-gcc (GCC) 15.2.0, GNU ld (GNU Binutils) 2.45) #1 SMP Fri Mar 20 16:12:05 MST 2026 > ... > [ 0.031929] 8<--- cut here --- > [ 0.031999] Unable to handle kernel NULL pointer dereference at virtual address 00000000 when write > [ 0.032172] [00000000] *pgd=00000000 > [ 0.032459] Internal error: Oops: 805 [#1] SMP ARM > [ 0.032902] Modules linked in: > [ 0.033466] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc4-00017-g8e8e23dea43e #1 VOLUNTARY > [ 0.033658] Hardware name: Generic DT based system > [ 0.033770] PC is at build_sched_domains+0x7d0/0x1628 For me, this points to: $ scripts/faddr2line vmlinux build_sched_domains+0x7d0/0x1628 build_sched_domains+0x7d0/0x1628: find_next_bit_wrap at include/linux/find.h:455 (inlined by) build_sched_groups at kernel/sched/topology.c:1255 (inlined by) build_sched_domains at kernel/sched/topology.c:2603 which is the: span = sched_domain_span(sd); for_each_cpu_wrap(i, span, cpu) /* Here */ { ... } in build_sched_groups() so we are likely going off the allocated cpumask size but before that, we do this in the caller: sd->span_weight = cpumask_weight(sched_domain_span(sd)); which should have crashed too if we had a NULL pointer in the cpumask range. So I'm at a loss. Maybe the pc points to a different location in your build? -- Thanks and Regards, Prateek