linux-kernel - [peterz-queue:sched/flat] [sched/fair] 596061ecef: Oops

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Message-ID: <202602061046.eee12820-lkp@intel.com>
Date: Fri, 6 Feb 2026 11:15:40 +0800
From: kernel test robot <oliver.sang@...el.com>
To: Peter Zijlstra <peterz@...radead.org>
CC: <oe-lkp@...ts.linux.dev>, <lkp@...el.com>, <linux-kernel@...r.kernel.org>,
	<aubrey.li@...ux.intel.com>, <yu.c.chen@...el.com>, <oliver.sang@...el.com>
Subject: [peterz-queue:sched/flat] [sched/fair]  596061ecef: Oops



Hello,

kernel test robot noticed "Oops" on:

commit: 596061ecef8ab0561e92704bcdc166fb91ecdec1 ("sched/fair: Add newidle balance to pick_task_fair()")
https://git.kernel.org/cgit/linux/kernel/git/peterz/queue.git sched/flat

in testcase: stress-ng
version: stress-ng-x86_64-30f8b2f05-1_20251212
with following parameters:

	nr_threads: 100%
	testtime: 60s
	test: pipeherd
	cpufreq_governor: performance



config: x86_64-rhel-9.4
compiler: gcc-14
test machine: 192 threads 2 sockets Intel(R) Xeon(R) 6740E  CPU @ 2.4GHz (Sierra Forest) with 256G memory

(please refer to attached dmesg/kmsg for entire log/backtrace)



If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@...el.com>
| Closes: https://lore.kernel.org/oe-lkp/202602061046.eee12820-lkp@intel.com



[  368.640460][T10417] #PF: supervisor write access in kernel mode
[  368.640462][T10417] #PF: error_code(0x0002) - not-present page
[  368.640465][T10417] PGD 0 P4D 0
[  368.643193][T10417] Oops: Oops: 0002 [#1] SMP NOPTI
[  368.643198][T10417] CPU: 8 UID: 0 PID: 10417 Comm: stress-ng-pipeh Tainted: G S                  6.19.0-rc6-00148-g596061ecef8a #1 PREEMPTLAZY
[  368.646302][T10417] Tainted: [S]=CPU_OUT_OF_SPEC
[  368.646303][T10417] Hardware name: IEIT SYSTEMS NF5180-M8-A0-R0-00/NF5180-M8-A0-R0-00, BIOS 00.14.04 09/23/2024
[  368.646304][T10417] RIP: 0010:pick_next_task_fair (kernel/sched/sched.h:2673 kernel/sched/fair.c:9114)
[  368.649951][T10417] Code: 48 89 c3 49 81 be a8 02 00 00 a8 e1 bb 82 0f 85 e5 00 00 00 49 c7 86 a0 02 00 00 00 00 00 00 49 89 dd 49 8b 84 24 88 0a 00 00 <48> 89 83 a0 02 00 00 49 c7 84 24 88 0a 00 00 00 00 00 00 4c 39 f3
All code
========
   0:	48 89 c3             	mov    %rax,%rbx
   3:	49 81 be a8 02 00 00 	cmpq   $0xffffffff82bbe1a8,0x2a8(%r14)
   a:	a8 e1 bb 82 
   e:	0f 85 e5 00 00 00    	jne    0xf9
  14:	49 c7 86 a0 02 00 00 	movq   $0x0,0x2a0(%r14)
  1b:	00 00 00 00 
  1f:	49 89 dd             	mov    %rbx,%r13
  22:	49 8b 84 24 88 0a 00 	mov    0xa88(%r12),%rax
  29:	00 
  2a:*	48 89 83 a0 02 00 00 	mov    %rax,0x2a0(%rbx)		<-- trapping instruction
  31:	49 c7 84 24 88 0a 00 	movq   $0x0,0xa88(%r12)
  38:	00 00 00 00 00 
  3d:	4c 39 f3             	cmp    %r14,%rbx

Code starting with the faulting instruction
===========================================
   0:	48 89 83 a0 02 00 00 	mov    %rax,0x2a0(%rbx)
   7:	49 c7 84 24 88 0a 00 	movq   $0x0,0xa88(%r12)
   e:	00 00 00 00 00 
  13:	4c 39 f3             	cmp    %r14,%rbx


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260206/202602061046.eee12820-lkp@intel.com



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki