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McKenney" , "Gautham R. Shenoy" , Florian Weimer , Tim Chen , Yury Norov References: <20251029123717.886619142@linutronix.de> <47e73026-390e-40d6-a860-10e9378a3bf3@linux.ibm.com> Content-Language: en-US In-Reply-To: <47e73026-390e-40d6-a860-10e9378a3bf3@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=K+gv3iWI c=1 sm=1 tr=0 ts=69030864 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=IkcTkHD0fZMA:10 a=x6icFKpwvdMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VwQbUJbxAAAA:8 a=EGPLfLqNyrsdq5xICDsA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=cPQSjfK2_nFv0Q5t_7PE:22 X-Proofpoint-ORIG-GUID: Y0DABLwWwSPLZ9Ardv4z5MQ-D7OgMk68 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMDI4MDE2NiBTYWx0ZWRfXxLTEgi3U0/kp GJtq36c20Q/egvqCejpxAUlF9PyCZ39FB5UKZtfaKsi92etEy+XXQu+lOLkgvayKgqO1JBN+6xn 71AUEj31vtGQM2znKJEg6D4loXy4Ua2epw3x1prjsJXaAqM56BFAH2RdcpAeAwRn9AZ39T3Y10S jWnPMV23Qd2OkTXhT7wMH7wkSRAkIT3x9M/F9Sif96F6FInVcyjqHO3Xvxs1D3tQgyGw4EAGefF kBVtVtCunltILCXY2Ha0HwhFzRvnzxtAne4d5YfUBA8njHU61/SmeVpMrylXcmiBTvtQuQih+vF Exz8osPW+YYU++Zk/e/b0wXyZOHtn3lf/uGUnFEbL0Pw7Qj7Hp6hTJbdF4YdRZvcQeVgIJeneKg rqE2gik509A80mdGSiHfHMKA71AQ/Q== X-Proofpoint-GUID: YLrkVdXazFGtC-ICCRzMxBZdxNdYSwY0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-10-30_01,2025-10-29_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 priorityscore=1501 impostorscore=0 suspectscore=0 adultscore=0 clxscore=1015 malwarescore=0 phishscore=0 spamscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2510240000 definitions=main-2510280166 On 10/30/25 10:30 AM, Shrikanth Hegde wrote: > Hi Thomas. >> +---------------------- >>   kernel/sched/sched.h           |  395 ++++++++----------- >>   kernel/signal.c                |    2 >>   lib/bitmap.c                   |    6 >>   16 files changed, 727 insertions(+), 823 deletions(-) >> >> > > I am running into crash at boot on power10 pseries. > Thought of putting it here first. Me trying to figure out why. > > I am using your tree. > git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git > > commit 789ff6e7cc5aa423473eb135f94812fe77b8aeab (HEAD -> rseq/cid, > origin/rseq/cid) > Author: Thomas Gleixner > Date:   Tue Oct 14 10:51:04 2025 +0200 > >     sched/mmcid: Switch over to the new mechanism > > > Oops: Kernel access of bad area, sig: 7 [#3] > LE PAGE_SIZE=64K MMU=Radix  SMP NR_CPUS=8192 NUMA pSeries > Modules linked in: drm drm_panel_orientation_quirks xfs sd_mod sg > ibmvscsi ibmveth scsi_transport_srp pseries_wdt dm_mirror dm_region_hash > dm_log dm_mod fuse > CPU: 96 UID: 0 PID: 0 Comm: swapper/96 Tainted: G      D W > 6.18.0-rc3+ #4 PREEMPT(lazy) > Tainted: [D]=DIE, [W]=WARN > NIP [c0000000001b5c10] mm_cid_switch_to+0x58/0x52c > LR [c000000001117c84] __schedule+0x4bc/0x760 > Call Trace: > [c00000668367fde0] [c0000000001b53c8] __pick_next_task+0x60/0x2ac > (unreliable) > [c00000668367fe40] [c000000001117a14] __schedule+0x24c/0x760 > [c00000668367fee0] [c0000000011183d0] schedule_idle+0x3c/0x64 > [c00000668367ff10] [c0000000001f2470] do_idle+0x15c/0x1ac > [c00000668367ff60] [c0000000001f2788] cpu_startup_entry+0x4c/0x50 > [c00000668367ff90] [c00000000005ef20] start_secondary+0x284/0x288 > [c00000668367ffe0] [c00000000000e158] start_secondary_prolog+0x10/0x14 > Issue happens with NR_CPUS=8192. System boots fine with NR_CPUS=2048