[LTP] [PATCH] sched/fork: Fix timer_slack_ns inheritance for RT tasks

Thu May 28 06:50:39 CEST 2026

Hello,

kernel test robot noticed "ltp.prctl08.fail" on:

commit: 2aa2f0a955c7459279e861f62c770f5f81d64f4f ("[PATCH] sched/fork: Fix timer_slack_ns inheritance for RT tasks")
url: https://github.com/intel-lab-lkp/linux/commits/Xiao-Feng-via-B4-Relay/sched-fork-Fix-timer_slack_ns-inheritance-for-RT-tasks/20260520-210956
patch link: https://lore.kernel.org/all/20260520-sched-fork-fix-timer-slack-v1-1-d4fc937245b2@xiaomi.com/
patch subject: [PATCH] sched/fork: Fix timer_slack_ns inheritance for RT tasks

in testcase: ltp
version: 
with following parameters:

	disk: 1HDD
	fs: ext4
	test: syscalls-05

config: x86_64-rhel-9.4-ltp
compiler: gcc-14
test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @ 3.00GHz (Cascade Lake) with 128G 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@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202605281011.2ba77cc3-lkp@intel.com

2026-05-29 16:17:35 kirk -f syscalls-05 --tmp-dir /fs/sda1/tmpdir
Host information
	Hostname:   lkp-csl-d02
	Python:     3.13.5 (main, Jun 25 2025, 18:55:22) [GCC 14.2.0]
	Directory:  /fs/sda1/tmpdir/kirk.root/tmp0lg24sa6

Connecting to SUT: default

Suite: syscalls-05
──────────────────

...

[1;37mprctl02: [0m[1;32mpass[0m | [1;33mtainted[0m  (0.011s)
[1;37mprctl08: [0m[1;31mfail[0m | [1;33mtainted[0m  (0.011s)   <---
[1;37mpreadv203: [0m[1;36mskip[0m | [1;33mtainted[0m  (47.775s)
[1;37mprofil01: [0m[1;32mpass[0m | [1;33mtainted[0m  (5.005s)

...

Execution time: 9m 8s

Disconnecting from SUT: default

Target information
──────────────────
Kernel:   Linux 7.1.0-rc4+ #1 SMP PREEMPT_DYNAMIC Tue May 26 16:01:55 CST 2026
Cmdline:  ip=::::lkp-csl-d02::dhcp
          root=/dev/ram0
          RESULT_ROOT=/result/ltp/1HDD-ext4-syscalls-05/lkp-csl-d02/debian-13-x86_64-20250902.cgz/x86_64-rhel-9.4-ltp/gcc-14/2aa2f0a955c7459279e861f62c770f5f81d64f4f/0
          BOOT_IMAGE=/pkg/linux/x86_64-rhel-9.4-ltp/gcc-14/2aa2f0a955c7459279e861f62c770f5f81d64f4f/vmlinuz-7.1.0-rc4+
          branch=linux-devel/devel-hourly-20260521-050335
          job=/lkp/jobs/scheduled/lkp-csl-d02/ltp-1HDD-ext4-syscalls-05-debian-13-x86_64-20250902.cgz-2aa2f0a955c7-20260526-26280-5dbkeb-0.yaml
          user=lkp
          ARCH=x86_64
          kconfig=x86_64-rhel-9.4-ltp
          commit=2aa2f0a955c7459279e861f62c770f5f81d64f4f
          intremap=posted_msi
          acpi_rsdp=0x36983000
          max_uptime=14400
          LKP_SERVER=10.239.97.5
          nokaslr
          selinux=0
          debug
          apic=debug
          sysrq_always_enabled
          rcupdate.rcu_cpu_stall_timeout=100
          net.ifnames=0
          printk.devkmsg=on
          panic=-1
          softlockup_panic=1
          nmi_watchdog=panic
          oops=panic
          load_ramdisk=2
          prompt_ramdisk=0
          drbd.minor_count=8
          systemd.log_level=err
          ignore_loglevel
          console=tty0
          earlyprintk=ttyS0,115200
          console=ttyS0,115200
          vga=normal
          rw
          keep_initrds=/osimage/pkg/debian-13-x86_64-20250902.cgz/ltp-x86_64-8cd7644a5-1_20260514.cgz
          acpi_rsdp=0x36983000
Machine:  unknown
Arch:     x86_64
RAM:      114660756 kB
Swap:     0 kB
Distro:   debian 13

────────────────────────
      TEST SUMMARY
────────────────────────
Suite:   syscalls-05
Runtime: 9m 4s
Runs:    189

Results:
    Passed:   1293
    Failed:   3
    Broken:   0
    Skipped:  38
    Warnings: 0

[1;31mFailures:[0m
    • prctl08

Session stopped

The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260528/202605281011.2ba77cc3-lkp@intel.com

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