sysfs irq
/proc/stat
算是一个 legacy 统计接口了
cpu 51210 548 98120 18538659 919 10581 19549 47 0 0
cpu0 11068 109 14285 4653460 210 1499 904 8 0 0
cpu1 12252 234 27207 4629717 157 3606 6422 13 0 0
cpu2 15219 90 35241 4611840 192 3292 11709 15 0 0
cpu3 12669 113 21385 4643639 358 2182 512 8 0 0
intr 22062934 0 39952 3835773 0 0 0 122 0 0 0 6111010 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 1 0 0 11095 9747 10090 20049 0 5922239 0 0
21 0 5917379 3269 0 99767 82123 0 0 0 20 21 0 0 0 0 0 0 2
56 0 0
ctxt 16649981
btime 1752935445
processes 27065
procs_running 1
procs_blocked 0
softirq 15316818 0 763086 307 11949992 0 0 2082 2091354 0 509997
/proc/softirq
不言自明，就是各个 softirq 再每一个 CPU 上执行的次数
🧀 cat /proc/softirqs
CPU0 CPU1 CPU2 CPU3
HI: 0 0 0 0
TIMER: 165934 214905 234256 140886
NET_TX: 102 41 40 123
NET_RX: 108032 5830758 5819179 84390
BLOCK: 0 0 0 0
IRQ_POLL: 0 0 0 0
TASKLET: 337 857 45 833
SCHED: 802183 448203 529477 289775
HRTIMER: 0 0 0 0
RCU: 136717 122756 127614 120001
/proc/irq/
- 代码跟踪 : 如何利用 /proc/irq 调整 io apic 的 cpu affinity
- 最后就是调用到 irq_chip::irq_set_affinity 的位置
- 并且和[^3] 中间描述的 ioapic 的中断选项完全相同
affinity :
- IRQ affinity on SMP. If this is an IPI related irq, then this is the mask of the CPUs to which an IPI can be sent. effective_affinity :
- The effective IRQ affinity on SMP as some irq chips do not allow multi CPU destinations. A subset of affinity.
- /proc/irq 的代码都在 kernel/irq/proc.c
配置中断亲和性
cat /proc/interrupts
157: 15603 16812 976943 29310 IR-PCI-MSIX-0000:01:00.0 1-edge enp1s0-TxRx-0
158: 967713 17281 23919 24808 IR-PCI-MSIX-0000:01:00.0 2-edge enp1s0-TxRx-1
159: 24484 1708690 27964 18901 IR-PCI-MSIX-0000:01:00.0 3-edge enp1s0-TxRx-2
160: 40130 22905 17792 23567 IR-PCI-MSIX-0000:01:00.0 4-edge enp1s0-TxRx-3
可以看到只有 enp1s0-TxRx-1 和 enp1s0-TxRx-2 被使用，这两个中断默认都是绑定一个 CPU 的
尝试修改 smp_affinity ，似乎没有结果:
🧀 echo 7 > /proc/irq/158/smp_affinity
~/.ssh 🐶
🧀 cat /proc/irq/159/smp_affinity
7
~/.ssh 🐶
🧀 cat /proc/irq/159/effective_affinity_list
1
effective_affinity_list 总是一个数字
@[
apic_update_irq_cfg+1
assign_vector_locked+176
apic_set_affinity+96
intel_ir_set_affinity+56
msi_domain_set_affinity+77
irq_do_set_affinity+448
irq_set_affinity_locked+409
irq_set_affinity+63
write_irq_affinity.isra.0+239
proc_reg_write+90
vfs_write+245
ksys_write+109
do_syscall_64+130
entry_SYSCALL_64_after_hwframe+118
]: 1
在 apic_update_irq_cfg 中，参数就一个 cpu ，如何从 vector 中选择的看 assign_vector_locked
/sys/kernel/irq
至此，linux irq 的含义是很清晰的
static struct attribute *irq_attrs[] = {
&per_cpu_count_attr.attr,
&chip_name_attr.attr,
&hwirq_attr.attr,
&type_attr.attr,
&wakeup_attr.attr,
&name_attr.attr,
&actions_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(irq);
在 kernel/irq/irqdesc.c 中 ，使用 irq_to_desc 来获取 。
🤒 grep -r .
wakeup:disabled
hwirq:1
actions:virtio3-input.0
type:edge
chip_name:PCI-MSIX-0000:00:05.0
per_cpu_count:0,0,0,18437,0,0,0,221,0,0,8,1026968,0,0,0,0,13,0,50895,0,0,5390,0
3,148024189,0,0,0,458912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
,0,0,0,0,0,0,0
name:edge
和 cat /proc/interrupts 中内容基本相同:
🧀 cat /proc/interrupts | grep virtio3-input.0
72: 0 0 0 18437 0 0 0 221 0 0 8 1026968 0 0 0 0 13 0 50895 0 0 5390 0 3 148024189 0 0 0 466069 0 0 0 PCI-MSIX-0000:00:05.0 1-edge virtio3-input.0
除了 hwirq
/proc/interrupts
➜ irq cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
0: 8 0 0 0 0 0 0 0 IR-IO-APIC 2-edge timer
1: 2716 0 0 0 0 0 0 14 IR-IO-APIC 1-edge i8042
8: 0 1 0 0 0 0 0 0 IR-IO-APIC 8-edge rtc0
9: 4 13 0 0 0 0 0 0 IR-IO-APIC 9-fasteoi acpi
12: 83 0 0 0 0 0 143 0 IR-IO-APIC 12-edge i8042
14: 134097 0 31 0 0 0 0 0 IR-IO-APIC 14-fasteoi INT344B:00
16: 1381211 0 0 1125 0 0 0 0 IR-IO-APIC 16-fasteoi idma64.0, i801_smbus, i2c_designware.0
17: 0 0 0 0 0 0 0 0 IR-IO-APIC 17-fasteoi idma64.1, i2c_designware.1
120: 0 0 0 0 0 0 0 0 DMAR-MSI 0-edge dmar0
121: 0 0 0 0 0 0 0 0 DMAR-MSI 1-edge dmar1
122: 0 0 0 0 0 0 0 0 IR-PCI-MSI 458752-edge PCIe PME, aerdrv
123: 0 0 0 0 0 0 0 0 IR-PCI-MSI 473088-edge PCIe PME, aerdrv
124: 0 0 0 0 0 0 0 0 IR-PCI-MSI 475136-edge PCIe PME, aerdrv
125: 674114 0 0 0 705672 6110 0 0 IR-PCI-MSI 327680-edge xhci_hcd
126: 0 31 0 0 0 0 0 0 IR-PCI-MSI 360448-edge mei_me
127: 134097 0 31 0 0 0 0 0 INT344B:00 99 ETD2303:00
128: 0 0 0 18 0 0 0 0 IR-PCI-MSI 1572864-edge nvme0q0
129: 0 0 250 0 0 0 0 0 IR-PCI-MSI 514048-edge snd_hda_intel:card0
130: 0 0 0 0 19088 0 0 0 IR-PCI-MSI 1572865-edge nvme0q1
131: 0 9431 0 0 0 0 0 0 IR-PCI-MSI 1572866-edge nvme0q2
132: 0 0 8073 0 0 0 0 0 IR-PCI-MSI 1572867-edge nvme0q3
133: 0 0 0 9255 0 0 0 0 IR-PCI-MSI 1572868-edge nvme0q4
134: 0 0 0 0 0 7961 0 0 IR-PCI-MSI 1572869-edge nvme0q5
135: 0 0 0 0 0 0 10062 0 IR-PCI-MSI 1572870-edge nvme0q6
136: 2222 0 381984 0 22229 1531873 27420 9994 IR-PCI-MSI 32768-edge i915
137: 1429 164 31 368 1196 0 12158 75506 IR-PCI-MSI 1048576-edge iwlwifi
138: 32 0 27 0 0 0 15 0 IR-PCI-MSI 524288-edge nvkm
139: 0 0 0 0 0 0 0 8193 IR-PCI-MSI 1572871-edge nvme0q7
NMI: 29 74 74 74 74 72 69 69 Non-maskable interrupts
LOC: 1895402 1772361 1840003 1797418 1822740 2050418 1775710 1753250 Local timer interrupts
SPU: 0 0 0 0 0 0 0 0 Spurious interrupts
PMI: 29 74 74 74 74 72 69 69 Performance monitoring interrupts
IWI: 93 5 22562 9 1329 107699 1915 540 IRQ work interrupts
RTR: 0 0 0 0 0 0 0 0 APIC ICR read retries
RES: 376738 205460 116961 102464 83042 65067 57540 53069 Rescheduling interrupts
CAL: 171524 158205 159437 164110 160299 161635 165628 161995 Function call interrupts
TLB: 232182 234240 233417 235103 225417 227488 230138 229758 TLB shootdowns
TRM: 4 4 4 4 4 4 4 4 Thermal event interrupts
THR: 0 0 0 0 0 0 0 0 Threshold APIC interrupts
DFR: 0 0 0 0 0 0 0 0 Deferred Error APIC interrupts
MCE: 0 0 0 0 0 0 0 0 Machine check exceptions
MCP: 61 61 61 61 61 61 61 61 Machine check polls
ERR: 0
MIS: 0
PIN: 0 0 0 0 0 0 0 0 Posted-interrupt notification event
NPI: 0 0 0 0 0 0 0 0 Nested posted-interrupt event
PIW: 0 0 0 0 0 0 0 0 Posted-interrupt wakeup event
才发现，IR-IO-APIC 后面都是添加上设备的，IR-PCI-MSI 主要是和 pcie 相关的设备，而 local apic 的名称直接被该 interrupt 的名字替代了。
- 1572869-edge : 是什么鬼
尝试分析一下 /proc/interrupts 如何生成的:
-
在 kernel/irq/proc.c::show_interrupts 中间
-
/proc/interrupts : proc.c:show_interrupts() 的最后的描述，其实就是相关的 chip
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 0: 8 0 0 0 0 0 0 0 IR-IO-APIC 2-edge timer 1: 19619 0 0 0 0 0 0 3444 IR-IO-APIC 1-edge i8042 8: 0 1 0 0 0 0 0 0 IR-IO-APIC 8-edge rtc0 9: 46 68 0 0 0 0 0 0 IR-IO-APIC 9-fasteoi acpi 12: 384 0 0 0 0 0 143 0 IR-IO-APIC 12-edge i8042 14: 187427 0 28041 0 0 0 0 0 IR-IO-APIC 14-fasteoi INT344B:00
本站所有文章转发 CSDN 将按侵权追究法律责任，其它情况随意。