linux interrupt
2015-10-21
中断在内存在的数据视图
linux interrupt 在 linux 有两个比较重要的数据视图
- /proc/interrupts 文件
- /proc/irq/ 子目录
我们先来看看 /proc/interrupts 这个视图是怎么样的：
[root@docker221 ~]# cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
0: 101 0 0 0 0 0 0 0 IO-APIC-edge timer
1: 10 0 0 565 0 0 0 0 xen-pirq-ioapic-edge i8042
6: 3 0 0 0 0 0 0 0 xen-pirq-ioapic-edge floppy
7: 0 0 0 0 0 0 0 0 xen-pirq-ioapic-edge parport0
8: 2 0 0 0 0 0 0 0 xen-pirq-ioapic-edge rtc0
9: 0 0 0 0 0 0 0 0 IO-APIC-fasteoi acpi
12: 145 0 0 0 0 0 0 669 xen-pirq-ioapic-edge i8042
14: 0 0 0 0 0 0 0 0 IO-APIC-edge ata_piix
15: 92130 263609 247456 196365 248794 114265 192813 17237957 IO-APIC-edge ata_piix
23: 23 0 0 0 0 0 0 13 xen-pirq-ioapic-level uhci_hcd:usb1
64: 2844203322 0 0 0 0 0 0 0 xen-percpu-virq timer0
65: 4011288744 0 0 0 0 0 0 0 xen-percpu-ipi resched0
66: 149448119 0 0 0 0 0 0 0 xen-percpu-ipi callfunc0
67: 0 0 0 0 0 0 0 0 xen-percpu-virq debug0
68: 96677001 0 0 0 0 0 0 0 xen-percpu-ipi callfuncsingle0
69: 3927847 0 0 0 0 0 0 0 xen-percpu-ipi spinlock0
70: 0 2005575034 0 0 0 0 0 0 xen-percpu-virq timer1
71: 0 1703505472 0 0 0 0 0 0 xen-percpu-ipi resched1
72: 0 151484784 0 0 0 0 0 0 xen-percpu-ipi callfunc1
73: 0 0 0 0 0 0 0 0 xen-percpu-virq debug1
74: 0 106750775 0 0 0 0 0 0 xen-percpu-ipi callfuncsingle1
75: 0 3944086 0 0 0 0 0 0 xen-percpu-ipi spinlock1
76: 0 0 2341712910 0 0 0 0 0 xen-percpu-virq timer2
77: 0 0 1450048536 0 0 0 0 0 xen-percpu-ipi resched2
78: 0 0 128936788 0 0 0 0 0 xen-percpu-ipi callfunc2
79: 0 0 0 0 0 0 0 0 xen-percpu-virq debug2
80: 0 0 84814469 0 0 0 0 0 xen-percpu-ipi callfuncsingle2
81: 0 0 3601868 0 0 0 0 0 xen-percpu-ipi spinlock2
82: 0 0 0 2267335285 0 0 0 0 xen-percpu-virq timer3
83: 0 0 0 600257105 0 0 0 0 xen-percpu-ipi resched3
84: 0 0 0 133243573 0 0 0 0 xen-percpu-ipi callfunc3
85: 0 0 0 0 0 0 0 0 xen-percpu-virq debug3
86: 0 0 0 81093166 0 0 0 0 xen-percpu-ipi callfuncsingle3
87: 0 0 0 3502054 0 0 0 0 xen-percpu-ipi spinlock3
88: 0 0 0 0 2115301138 0 0 0 xen-percpu-virq timer4
89: 0 0 0 0 728657869 0 0 0 xen-percpu-ipi resched4
90: 0 0 0 0 132279720 0 0 0 xen-percpu-ipi callfunc4
91: 0 0 0 0 0 0 0 0 xen-percpu-virq debug4
92: 0 0 0 0 81400733 0 0 0 xen-percpu-ipi callfuncsingle4
93: 0 0 0 0 3427391 0 0 0 xen-percpu-ipi spinlock4
94: 0 0 0 0 0 2145376645 0 0 xen-percpu-virq timer5
95: 0 0 0 0 0 236524947 0 0 xen-percpu-ipi resched5
96: 0 0 0 0 0 132211572 0 0 xen-percpu-ipi callfunc5
97: 0 0 0 0 0 0 0 0 xen-percpu-virq debug5
98: 0 0 0 0 0 81880824 0 0 xen-percpu-ipi callfuncsingle5
99: 0 0 0 0 0 3590193 0 0 xen-percpu-ipi spinlock5
100: 0 0 0 0 0 0 2126495446 0 xen-percpu-virq timer6
101: 0 0 0 0 0 0 4269631923 0 xen-percpu-ipi resched6
102: 0 0 0 0 0 0 134202455 0 xen-percpu-ipi callfunc6
103: 0 0 0 0 0 0 0 0 xen-percpu-virq debug6
104: 0 0 0 0 0 0 81670546 0 xen-percpu-ipi callfuncsingle6
105: 0 0 0 0 0 0 3628607 0 xen-percpu-ipi spinlock6
106: 0 0 0 0 0 0 0 1584236686 xen-percpu-virq timer7
107: 0 0 0 0 0 0 0 2211547569 xen-percpu-ipi resched7
108: 0 0 0 0 0 0 0 131658570 xen-percpu-ipi callfunc7
109: 0 0 0 0 0 0 0 0 xen-percpu-virq debug7
110: 0 0 0 0 0 0 0 79512648 xen-percpu-ipi callfuncsingle7
111: 0 0 0 0 0 0 0 3875555 xen-percpu-ipi spinlock7
112: 347 0 0 0 0 0 4 0 xen-dyn-event xenbus
113: 8536 0 0 0 0 0 0 516134858 xen-dyn-event blkif
114: 749775929 0 0 0 0 0 0 0 xen-dyn-event eth0
NMI: 0 0 0 0 0 0 0 0 Non-maskable interrupts
LOC: 0 0 0 0 0 0 0 0 Local timer interrupts
SPU: 0 0 0 0 0 0 0 0 Spurious interrupts
PMI: 0 0 0 0 0 0 0 0 Performance monitoring interrupts
IWI: 77770231 59439640 41287756 39469408 41371499 41275040 40654227 41210691 IRQ work interrupts
RTR: 0 0 0 0 0 0 0 0 APIC ICR read retries
RES: 4011288745 1703505472 1450048536 600257105 728657869 236524947 4269631923 2211547569 Rescheduling interrupts
CAL: 4286015824 4285752264 4287125822 4287268137 4286953722 4287128322 4287081469 4286621008 Function call interrupts
TLB: 255076592 267450591 221592731 222035898 221694027 221931370 223758828 219517506 TLB shootdowns
TRM: 0 0 0 0 0 0 0 0 Thermal event interrupts
THR: 0 0 0 0 0 0 0 0 Threshold APIC interrupts
MCE: 0 0 0 0 0 0 0 0 Machine check exceptions
MCP: 42321 42321 42321 42321 42321 42321 42321 42321 Machine check polls
ERR: 0
MIS: 0
[root@docker221 ~]#
其中每列依次为：irq 的编号，irq 中 cup 上的累积处理次数，中断控制器的名字，irq的名字，以及驱动程序注册该irq时使用的名字。
其中 /proc/irq 的每个子目录对应的是一个 interrupt 编号。
[root@docker221 114]# pwd
/proc/irq/114
[root@docker221 114]# ls
affinity_hint eth0 node smp_affinity smp_affinity_list spurious
其中比较常用的文件的作用：
- smp_affinity：irq和cpu之间的亲缘绑定关系
- affinity_hint：只读条目，用于用户空间做irq平衡只用
- spurious：可以获得该irq被处理和未被处理的次数的统计信息
参考
- http://blog.csdn.net/droidphone/article/details/7445825
- https://www.ibm.com/developerworks/cn/linux/l-cn-linuxkernelint/
