linux/Documentation
Li RongQing e700f5d156 watchdog: softlockup: panic when lockup duration exceeds N thresholds
The softlockup_panic sysctl is currently a binary option: panic
immediately or never panic on soft lockups.

Panicking on any soft lockup, regardless of duration, can be overly
aggressive for brief stalls that may be caused by legitimate operations. 
Conversely, never panicking may allow severe system hangs to persist
undetected.

Extend softlockup_panic to accept an integer threshold, allowing the
kernel to panic only when the normalized lockup duration exceeds N
watchdog threshold periods.  This provides finer-grained control to
distinguish between transient delays and persistent system failures.

The accepted values are:
- 0: Don't panic (unchanged)
- 1: Panic when duration >= 1 * threshold (20s default, original behavior)
- N > 1: Panic when duration >= N * threshold (e.g., 2 = 40s, 3 = 60s.)

The original behavior is preserved for values 0 and 1, maintaining full
backward compatibility while allowing systems to tolerate brief lockups
while still catching severe, persistent hangs.

[lirongqing@baidu.com: v2]
  Link: https://lkml.kernel.org/r/20251218074300.4080-1-lirongqing@baidu.com
Link: https://lkml.kernel.org/r/20251216074521.2796-1-lirongqing@baidu.com
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:44:20 -08:00
..
ABI treewide: Update email address 2026-01-11 06:09:11 -10:00
accel accel/qaic: Separate DBC_STATE_* definition list 2025-11-10 14:50:06 -07:00
accounting Documentation: taskstats: Reindent payload kinds list 2025-11-10 12:52:12 -07:00
admin-guide watchdog: softlockup: panic when lockup duration exceeds N thresholds 2026-01-20 19:44:20 -08:00
arch treewide: Update email address 2026-01-11 06:09:11 -10:00
block
bpf docs: bpf: map_array: Specify BPF_MAP_TYPE_PERCPU_ARRAY value size limit 2025-11-25 14:32:00 -08:00
cdrom
core-api treewide: Update email address 2026-01-11 06:09:11 -10:00
cpu-freq
crypto This update includes the following changes: 2025-12-03 11:28:38 -08:00
dev-tools There are no significant series in this small merge. Please see the 2025-12-13 20:55:12 +12:00
devicetree phy fixes for 6.19 2026-01-18 13:18:40 -08:00
doc-guide docs: parse-headers.rst: Fix a typo 2025-11-18 09:13:40 -07:00
driver-api treewide: Update email address 2026-01-11 06:09:11 -10:00
edac
fault-injection
fb
features Apart from the usual small churn, we have 2025-12-05 16:30:56 -08:00
filesystems filelock: allow lease_managers to dictate what qualifies as a conflict 2025-12-15 15:20:33 +01:00
firmware-guide Documentation: ACPI: i2c-muxes: fix I2C device references 2025-11-03 17:01:05 +01:00
firmware_class
fpga
gpu Extra drm-misc-next for v6.19-rc1: 2025-12-02 18:09:08 +10:00
hid Documentation: hid-alps: Format DataByte* subsection headings 2025-11-18 17:53:10 +01:00
hwmon hwmon: (DS620) Update broken Datasheet URL in driver documentation 2025-12-18 09:50:27 -08:00
i2c i2c: i801: Add support for Intel Nova Lake-S 2025-12-17 00:28:51 +01:00
iio Documentation: iio: ade9000, adis*, adx*: Convert IIO subsystem cross-references 2025-10-19 11:59:16 +01:00
images
infiniband
input Input: add ABS_SND_PROFILE 2025-12-18 21:34:42 -08:00
isdn
kbuild kbuild: doc: improve KBUILD_BUILD_TIMESTAMP documentation 2025-11-08 12:17:58 +01:00
kernel-hacking
leds leds: lp55xx_common: Enable use without FW_LOADER_USER_HELPER 2025-10-21 10:46:30 +01:00
litmus-tests
livepatch
locking documentation: seqlock: fix the wrong documentation of read_seqbegin_or_lock/need_seqretry 2025-10-21 12:31:56 +02:00
maintainer NFSD: Add a subsystem policy document 2025-11-16 18:20:11 -05:00
mhi
misc-devices Documentation: tps6594-pfsm: Fix macro cross-reference syntax 2025-11-10 12:54:49 -07:00
mm Docs/mm/allocation-profiling: describe sysctrl limitations in debug mode 2026-01-20 09:34:26 -08:00
netlabel
netlink Merge branch 'pm-em' 2026-01-16 16:16:24 +01:00
networking Documentation: net: dsa: mention simple HSR offload helpers 2025-12-01 16:51:55 -08:00
nvdimm
nvme
PCI Documentation: PCI: Amend error recovery doc with pci_save_state() rules 2025-11-24 16:59:10 -06:00
pcmcia
peci
power More power management updates for 6.19-rc1 2025-12-10 06:29:40 +09:00
process Documentation/process: maintainer-soc: Mark 'make' as commands 2026-01-07 17:47:43 +01:00
RCU doc: Update for SRCU-fast definitions and initialization 2025-11-05 23:58:30 +01:00
rust docs: rust: quick-start: add Debian 13 (Trixie) 2025-11-04 20:21:15 +01:00
scheduler
scsi
security Landlock update for v6.19-rc1 2025-12-06 09:52:41 -08:00
sound ASoC: doc: cs35l56: Update firmware filename description for B0 silicon 2025-11-03 13:09:14 +00:00
sphinx Documentation/sphinx/kernel_feat.py: use class directly 2025-11-21 10:32:30 -07:00
sphinx-static
spi
staging
sunrpc/xdr
target
tee
timers
tools rtla updaets for v6.19: 2025-12-05 09:34:01 -08:00
trace tracing updates for v6.19: 2025-12-05 09:51:37 -08:00
translations treewide: Update email address 2026-01-11 06:09:11 -10:00
usb
userspace-api media: Documentation: mali-c55: Use v4l2-isp version identifier 2026-01-06 10:14:13 +01:00
virt hyperv-next for v6.19 2025-12-09 06:10:17 +09:00
w1 docs: w1: fix w1-netlink invalid URL 2025-11-05 11:23:39 -07:00
watchdog
wmi Merge branch 'fixes' of into for-next 2025-12-01 11:53:59 +02:00
.gitignore
.renames.txt
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py
docutils.conf
index.rst
Kconfig docs: move get_abi.py to tools/docs 2025-10-28 16:01:20 -06:00
Makefile docs: makefile: move rustdoc check to the build wrapper 2025-11-29 08:42:53 -07:00
memory-barriers.txt memory-barriers.txt: Sort wait_event* and wait_on_bit* list alphabetically 2025-11-08 19:02:26 -08:00
SubmittingPatches
subsystem-apis.rst