port-sparc/59825: futex_wake_op_op test hangs on qemu-sparc with TCX and -smp 2

[randrianasulu%gmail.com@localhost]

>Number:         59825
>Category:       port-sparc
>Synopsis:       futex_wake_op_op test hangs on qemu-sparc with TCX and -smp 2
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Dec 09 14:15:00 +0000 2025
>Originator:     Andrew Randrianasulu
>Release:        10.1
>Organization:
N/a
>Environment:
NetBSD 10.1_STABLE (GENERIC.MP) #0: Sat Nov 29 16:02:26 UTC 2025 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/sparc/compile/GENERIC.MP
>Description:
when I try to run  this specific atf test :

cd /usr/tests/lib/libc/sys

atf-run t_futex_ops

om emulated SparcStation 20 with two or more cpus (-smp param of qemu set to 2 or more, like  qemu-system-sparc -hda /mnt/zip/home/guest/QEMU/sparc-netbsd-15g-compressed-r1.qcow2   -smp 2 -accel tcg,thread=multi,tb-size=256 -M SS-20 ) test hang if executed on graphical console but successed if redirected to a file.

full output from success run:

Content-Type: application/X-atf-tps; version="3"

info: atf.version, Automated Testing Framework 0.20 (atf-0.20)
info: tests.root, /usr/tests/lib/libc/sys
info: time.start, Tue Dec 9 10:47:28 UTC 2025
info: uname.sysname, NetBSD
info: uname.nodename, sparky
info: uname.release, 10.1_STABLE
info: uname.version, NetBSD 10.1_STABLE (GENERIC.MP) #0: Sat Nov 29 16:02:26 UTC 2025 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/sparc/compile/GENERIC.MP
info: uname.machine, sparc
info: env, ENV=/root/.shrc
info: env, BLOCKSIZE=1k
info: env, PWD=/usr/tests/lib/libc/sys
info: env, HOME=/root
info: env, PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/pkg/sbin:/usr/pkg/bin:/usr/games:/usr/X11R7/bin:/usr/local/sbin:/usr/local/bin
info: env, HOST=sparky
info: env, TERM=wsvt25
info: env, OLDPWD=/root
info: env, USER=root
info: env, PKG_PATH=https://cdn.NetBSD.org/pub/pkgsrc/packages/NetBSD/sparc/10.1/All
info: env, LOGNAME=root
info: env, SHELL=/bin/sh
tps-count: 1
tp-start: 1765277249.675214, t_futex_ops, 22
tc-start: 1765277249.678201, futex_basic_wait_wake_private
tc-end: 1765277253.936527, futex_basic_wait_wake_private, passed
tc-start: 1765277253.947720, futex_basic_wait_wake_shared
tc-end: 1765277260.144741, futex_basic_wait_wake_shared, passed
tc-start: 1765277260.151372, futex_cmp_requeue
tc-end: 1765277262.315736, futex_cmp_requeue, passed
tc-start: 1765277262.321845, futex_requeue
tc-end: 1765277264.465738, futex_requeue, passed
tc-start: 1765277264.471735, futex_wait_evil_unmapped_anon
tc-end: 1765277265.608333, futex_wait_evil_unmapped_anon, passed
tc-start: 1765277265.622519, futex_wait_pointless_bitset
tc-end: 1765277265.691153, futex_wait_pointless_bitset, passed
tc-start: 1765277265.697928, futex_wait_timeout_deadline
tc-end: 1765277267.775763, futex_wait_timeout_deadline, passed
tc-start: 1765277267.783152, futex_wait_timeout_deadline_rt
tc-end: 1765277269.855497, futex_wait_timeout_deadline_rt, passed
tc-start: 1765277269.862629, futex_wait_timeout_relative
tc-end: 1765277271.945460, futex_wait_timeout_relative, passed
tc-start: 1765277271.951630, futex_wait_timeout_relative_rt
tc-end: 1765277274.25754, futex_wait_timeout_relative_rt, passed
tc-start: 1765277274.32725, futex_wait_wake_anon_bs_private
tc-end: 1765277278.195670, futex_wait_wake_anon_bs_private, passed
tc-start: 1765277278.201724, futex_wait_wake_anon_bs_shared
tc-end: 1765277283.391503, futex_wait_wake_anon_bs_shared, passed
tc-start: 1765277283.400261, futex_wait_wake_anon_bs_shared_proc
tc-end: 1765277288.608426, futex_wait_wake_anon_bs_shared_proc, passed
tc-start: 1765277288.614507, futex_wait_wake_bitset
tc-end: 1765277292.781116, futex_wait_wake_bitset, passed
tc-start: 1765277292.787704, futex_wait_wake_file_bs_cow_private
tc-end: 1765277296.962239, futex_wait_wake_file_bs_cow_private, passed
tc-start: 1765277296.971228, futex_wait_wake_file_bs_cow_shared
tc-end: 1765277302.167768, futex_wait_wake_file_bs_cow_shared, passed
tc-start: 1765277302.175894, futex_wait_wake_file_bs_private
tc-end: 1765277306.348402, futex_wait_wake_file_bs_private, passed
tc-start: 1765277306.356893, futex_wait_wake_file_bs_shared
tc-end: 1765277311.572644, futex_wait_wake_file_bs_shared, passed
tc-start: 1765277311.581061, futex_wait_wake_file_bs_shared_proc
tc-end: 1765277316.767563, futex_wait_wake_file_bs_shared_proc, passed
tc-start: 1765277316.776156, futex_wake_highest_pri
tc-end: 1765277319.941202, futex_wake_highest_pri, expected_failure, PR kern/55230: /usr/src/tests/lib/libc/sys/t_futex_ops.c:1447: waiter == lwp_data[1].threadid not met
tc-start: 1765277319.947254, futex_wake_op_cmp
tc-end: 1765277324.245692, futex_wake_op_cmp, passed
tc-start: 1765277324.252052, futex_wake_op_op
tc-end: 1765277324.466304, futex_wake_op_op, passed
tp-end: 1765277324.472838, t_futex_ops
info: time.end, Tue Dec 9 10:48:44 UTC 2025


>How-To-Repeat:
install tests.tgz while installing virtual qemu-system-sparc machine with netBSD 10.1

Undate kernel to latest MP

run qemu like this:
 qemu-system-sparc -hda /mnt/zip/home/guest/QEMU/sparc-netbsd-15g-compressed-r1.qcow2   -smp 2 -accel tcg,thread=multi,tb-size=256 -M SS-20

from graphical (tcx) console  

cd /usr/tests/lib/libc/sys
atf-run f_futext_ops without output redirection

It will hang, may be not each time but often enough for hanging atf test suite long before it hangs in another place with -smp 1
>Fix:
run qemu with -smp 1 or non-MP kernel