crash工具中，irq命令是用于显示和管理系统中的中断请求（IRQ）的信息和状态的命令。IRQ是一种硬件信号，用于通知处理器有某个设备需要其服务。irq命令有以下作用：
- 可以查看系统中所有活动的中断的信息，包括虚拟中断号、中断描述符、注册的中断处理函数、中断名称等。
- 可以查看实际使用的中断的信息，过滤掉没有被申请的虚拟中断号。
- 可以查看中断向量表，适用于Intel处理器。
- 可以查看注册的软中断，包括软中断号、软中断处理函数、软中断名称等。
- 可以查看中断的CPU亲和性值，即指定哪些CPU可以处理哪些中断。
- 可以查看系统中断的使用和统计信息，类似于
cat /proc/interrupts命令的输出。
- 列出再用irq
crash> irq -u |more
IRQ IRQ_DESC/_DATA IRQACTION NAME
0 ff352c0107c1c800 ffffffff91e200c0 "timer"
1 ff352c0107c1ca00 (unused)
2 ff352c0107c1cc00 (unused)
3 ff352c0107c1ce00 (unused)
4 ff352c0107c1d000 (unused)
5 ff352c0107c1d200 (unused)
6 ff352c0107c1d400 (unused)
7 ff352c0107c1d600 (unused)
8 ff352c0107c1d800 ff352c808b608900 "rtc0"
9 ff352c0107c1da00 ff352cfe7f2f8000 "acpi"
10 ff352c0107c1dc00 (unused)
11 ff352c0107c1de00 (unused)
12 ff352c0107c1e000 (unused)
13 ff352c0107c1e200 (unused)
14 ff352c0107c1e400 (unused)
15 ff352c0107c1e600 (unused)
16 ff352cfe7dd81a00 ff352c7e5f88c100 "i801_smbus"
17 ff352c7e7a46de00 (unused)
18 ff352c7e7dcaa400 (unused)
19 ff352c7e6e983e00 (unused)
120 ff352c0107c1ec00 ff352c0107c27500 "dmar8"
121 ff352c0107c1ee00 ff352c0107c27580 "dmar7"
122 ff352c0107c1f000 ff352c0107c27600 "dmar6"
123 ff352c0107c1f200 ff352c0107c27680 "dmar5"
124 ff352c8087c11e00 ff352c0107c27700 "dmar4"
125 ff352c8087c15800 ff352c0107c27780 "dmar3"
126 ff352c8087c15600 ff352c0107c27800 "dmar2"
127 ff352c8087c15000 ff352c0107c27880 "dmar1"
128 ff352c8087c16c00 ff352c0107c27900 "dmar0"
129 ff352c0107c1fe00 ff352c0107c27980 "dmar9"
130 ff352c7e7a46ac00 ff352c808b609800 "PCIe PME"
131 ff352c7e7a46fc00 ff352c808b609e00 "PCIe PME"
132 ff352c7e7a46a800 ff352c808b609400 "PCIe PME"irq命令的常用功能的用例如下：
-
irq：显示系统所有中断的使用信息，如虚拟中断号，中断的irq_desc，注册的irqaction以及名字。 -
irq -u：显示实际使用的中断的信息，去除哪些没有被申请的虚拟中断号。 -
irq -d：显示中断向量表，适用于Intel处理器。 -
irq -b：显示注册的软中断。 -
irq -a：显示中断的CPU亲和性值。 -
irq -s：显示系统中断的使用和统计信息，类似于cat /proc/interrupts命令的输出。如果想查看指定CPU上统计信息，可以使用irq -s -c a或者irq -s -c 1,3,6-9等参数。 -
列出所有中断下半部
crash> irq -b
SOFTIRQ_VEC ACTION
[0] ffffffff90cbb370 <tasklet_hi_action>
[1] ffffffff90d3c060 <run_timer_softirq>
[2] ffffffff9131ccf0 <net_tx_action>
[3] ffffffff91321660 <net_rx_action>
[4] ffffffff90ff9b70 <blk_done_softirq>
[5] ffffffff910578c0 <irq_poll_softirq>
[6] ffffffff90cbb390 <tasklet_action>
[7] ffffffff90cf7d80 <run_rebalance_domains>
[8] ffffffff90d3ec00 <hrtimer_run_softirq>
[9] ffffffff90d31870 <rcu_process_callbacks>- 获取给定CPU的irq状态
crash> irq -c 1 -s |more
CPU1
0: 0 IR-IO-APIC-edge timer
8: 0 IR-IO-APIC-edge rtc0
9: 26 IR-IO-APIC-fasteoi acpi
16: 0 IR-IO-APIC-fasteoi i801_smbus
120: 0 DMAR-MSI-edge dmar8
121: 0 DMAR-MSI-edge dmar7
122: 0 DMAR-MSI-edge dmar6
123: 0 DMAR-MSI-edge dmar5
124: 0 DMAR-MSI-edge dmar4
125: 0 DMAR-MSI-edge dmar3
126: 0 DMAR-MSI-edge dmar2
127: 0 DMAR-MSI-edge dmar1
128: 0 DMAR-MSI-edge dmar0
129: 0 DMAR-MSI-edge dmar9
130: 0 IR-PCI-MSI-edge PCIe PME
131: 0 IR-PCI-MSI-edge PCIe PME
132: 0 IR-PCI-MSI-edge PCIe PMENAME
irq - IRQ data
SYNOPSIS
irq [[[index ...] | -u ] | -d | -b | -a | -s [-c cpu]]
DESCRIPTION
This command collaborates the data in an irq_desc_t, along with its
associated hw_interrupt_type and irqaction structure data, into a
consolidated per-IRQ display. For kernel versions 2.6.37 and later
the display consists of the irq_desc/irq_data address, its irqaction
address(es), and the irqaction name strings. Alternatively, the
intel interrupt descriptor table, bottom half data, cpu affinity for
in-use irqs, or kernel irq stats may be displayed. If no index value
argument(s) nor any options are entered, the IRQ data for all IRQs will
be displayed.
index a valid IRQ index.
-u dump data for in-use IRQs only.
-d dump the intel interrupt descriptor table.
-b dump bottom half data.
-a dump cpu affinity for in-use IRQs.
-s dump the kernel irq stats; if no cpu specified with -c, the
irq stats of all cpus will be displayed.
-c cpu only usable with the -s option, dump the irq stats of the
specified cpu[s]; cpu can be specified as "1,3,5", "1-3",
"1,3,5-7,10", "all", or "a" (shortcut for "all").
EXAMPLES
Display the relevant data for IRQ 18 from a pre-2.6.37 kernel:
crash> irq 18
IRQ: 18
STATUS: 0
HANDLER: c02301e0 <ioapic_level_irq_type>
typename: c01f9e0c "IO-APIC-level"
startup: c0110234 <unmask_IO_APIC_irq>
shutdown: c01101cc <mask_IO_APIC_irq>
handle: c0110518 <do_level_ioapic_IRQ>
enable: c0110234 <unmask_IO_APIC_irq>
disable: c01101cc <mask_IO_APIC_irq>
ACTION: c009c6b0
handler: c01ce818 <do_aic7xxx_isr>
flags: 4000000 (SA_SHIRQ)
mask: 0
name: c0217780 "aic7xxx"
dev_id: c0090078
next: c009c770
ACTION: c009c770
handler: c01ce818 <do_aic7xxx_isr>
flags: 4000000 (SA_SHIRQ)
mask: 0
name: c0217780 "aic7xxx"
dev_id: c0091078
next: 0
DEPTH: 0
Display the relevant data for IRQ 21 from a 2.6.37 kernel:
crash> irq 21
IRQ IRQ_DESC/_DATA IRQACTION NAME
21 ffff88003787f780 ffff8800379a8b40 "ehci_hcd:usb2"
ffff8800379cbac0 "uhci_hcd:usb5"
ffff8800379cb140 "uhci_hcd:usb7"
Display the intel interrupt descriptor table entries:
crash> irq -d
[0] divide_error
[1] debug
[2] nmi
[3] int3
[4] overflow
[5] bounds
[6] invalid_op
[7] device_not_available
[8] double_fault
[9] coprocessor_segment_overrun
[10] invalid_TSS
[11] segment_not_present
[12] stack_segment
[13] general_protection
[14] page_fault
[15] spurious_interrupt_bug
[16] coprocessor_error
[17] alignment_check
[18] ignore_int
[19] ignore_int
[20] ignore_int
[21] ignore_int
...
[250] IRQ0xda_interrupt
[251] IRQ0xdb_interrupt
[252] IRQ0xdc_interrupt
[253] IRQ0xdd_interrupt
[254] IRQ0xde_interrupt
[255] spurious_interrupt
Display the bottom half data:
crash> irq -b
SOFTIRQ_VEC ACTION
[0] ffffffff81068f60 <tasklet_hi_action>
[1] ffffffff81071b80 <run_timer_softirq>
[2] ffffffff813e6f30 <net_tx_action>
[3] ffffffff813ee370 <net_rx_action>
[4] ffffffff81211a60 <blk_done_softirq>
[5] ffffffff812122f0 <blk_iopoll_softirq>
[6] ffffffff81069090 <tasklet_action>
[7] ffffffff81058830 <run_rebalance_domains>
[8] ffffffff81087f00 <run_hrtimer_softirq>
[9] ffffffff810ca7a0 <rcu_process_callbacks>
Display the cpu affinity for in-use IRQs:
crash> irq -a
IRQ NAME AFFINITY
0 timer 0-23
1 i8042 0-23
8 rtc0 0-23
9 acpi 0-23
16 ehci_hcd:usb2,uhci_hcd:usb3,uhci_hcd:usb6 0,6,18
17 uhci_hcd:usb4,uhci_hcd:usb7 0-23
18 ehci_hcd:usb1,uhci_hcd:usb5,uhci_hcd:usb8,ioc0 0,11,23
24 dmar0 0
35 pciehp 0-23
36 pciehp 0-23
37 pciehp 0-23
38 pciehp 0-23
39 megasas 0-5,12-17
40 lpfc:sp 0-5,12-17
41 lpfc:fp 0,6-11,18-23
42 lpfc:sp 0,6-11,18-23
43 lpfc:fp 0,6-11,18-23
...
80 ioat-msix 0-23
81 ioat-msix 0-23
82 ioat-msix 0-23
83 ioat-msix 0-23
84 ioat-msix 0-23
85 ioat-msix 0-23
86 ioat-msix 0-23
87 ioat-msix 0-23
88 eth4 0,17
Display the kernel irq stats:
crash>irq -c 0,2 -s
CPU0 CPU2
0: 2068161471 0 IR-IO-APIC-edge timer
1: 9 0 IR-IO-APIC-edge i8042
8: 1 0 IR-IO-APIC-edge rtc0
9: 0 0 IR-IO-APIC-fasteoi acpi
16: 36 0 IR-IO-APIC-fasteoi ehci_hcd:usb2
...
85: 3 0 IR-PCI-MSI-edge ioat-msix
86: 3 0 IR-PCI-MSI-edge ioat-msix
87: 3 0 IR-PCI-MSI-edge ioat-msix
88: 24 295 IR-PCI-MSI-edge eth4