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Bitao Hu e9a9292e23 watchdog/softlockup: Report the most frequent interrupts
When the watchdog determines that the current soft lockup is due to an
interrupt storm based on CPU utilization, reporting the most frequent
interrupts could be good enough for further troubleshooting.

Below is an example of interrupt storm. The call tree does not provide
useful information, but analyzing which interrupt caused the soft lockup by
comparing the counts of interrupts during the lockup period allows to
identify the culprit.

[  638.870231] watchdog: BUG: soft lockup - CPU#9 stuck for 26s! [swapper/9:0]
[  638.870825] CPU#9 Utilization every 4s during lockup:
[  638.871194]  #1:   0% system,          0% softirq,   100% hardirq,     0% idle
[  638.871652]  #2:   0% system,          0% softirq,   100% hardirq,     0% idle
[  638.872107]  #3:   0% system,          0% softirq,   100% hardirq,     0% idle
[  638.872563]  #4:   0% system,          0% softirq,   100% hardirq,     0% idle
[  638.873018]  #5:   0% system,          0% softirq,   100% hardirq,     0% idle
[  638.873494] CPU#9 Detect HardIRQ Time exceeds 50%. Most frequent HardIRQs:
[  638.873994]  #1: 330945      irq#7
[  638.874236]  #2: 31          irq#82
[  638.874493]  #3: 10          irq#10
[  638.874744]  #4: 2           irq#89
[  638.874992]  #5: 1           irq#102
...
[  638.875313] Call trace:
[  638.875315]  __do_softirq+0xa8/0x364

Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Liu Song <liusong@linux.alibaba.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240411074134.30922-6-yaoma@linux.alibaba.com
2024-04-12 17:08:06 +02:00
arch genirq: Convert kstat_irqs to a struct 2024-04-12 17:08:05 +02:00
block
certs
crypto RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
Documentation dt-bindings: interrupt-controller: Add RISC-V advanced PLIC 2024-03-25 17:38:28 +01:00
drivers irqchip/loongson: Select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP for IRQ_LOONGARCH_CPU 2024-04-09 11:03:16 +02:00
fs A patch to minimize blockage when processing very large batches of 2024-03-22 11:15:45 -07:00
include genirq: Provide a snapshot mechanism for interrupt statistics 2024-04-12 17:08:05 +02:00
init RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
io_uring
ipc
kernel watchdog/softlockup: Report the most frequent interrupts 2024-04-12 17:08:06 +02:00
lib watchdog/softlockup: Low-overhead detection of interrupt storm 2024-04-12 17:08:05 +02:00
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mm RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
net Including fixes from CAN, netfilter, wireguard and IPsec. 2024-03-21 14:50:39 -07:00
rust Kbuild updates for v6.9 2024-03-21 14:41:00 -07:00
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scripts genirq: Convert kstat_irqs to a struct 2024-04-12 17:08:05 +02:00
security
sound sound fixes #2 for 6.9-rc2 2024-03-22 09:44:19 -07:00
tools RISC-V Patches for the 6.9 Merge Window 2024-03-22 10:41:13 -07:00
usr
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.mailmap Char/Misc and other driver subsystem updates for 6.9-rc1 2024-03-21 13:21:31 -07:00
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MAINTAINERS genirq: Update MAINTAINERS to include interrupt related header files 2024-04-11 12:29:40 +02:00
Makefile Linux 6.9-rc1 2024-03-24 14:10:05 -07:00
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