systemd-udevd为什么会调用两次？

[yangzhengbao]

[ 2.663756] systemd-udevd[96]: starting version 204
[ 2.732619] ahci 0000:00:11.0: version 3.0
[ 2.733171] ahci 0000:00:11.0: AHCI 0001.0200 32 slots 4 ports 3 Gbps 0xf impl SATA mode
[ 2.733179] ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio slum part
[ 2.734604] scsi0 : ahci
[ 2.734823] scsi1 : ahci
[ 2.735007] scsi2 : ahci
[ 2.735202] scsi3 : ahci
[ 2.735351] ata1: SATA max UDMA/133 abar m1024@0xfeb4f000 port 0xfeb4f100 irq 19
[ 2.735357] ata2: SATA max UDMA/133 abar m1024@0xfeb4f000 port 0xfeb4f180 irq 19
[ 2.735362] ata3: SATA max UDMA/133 abar m1024@0xfeb4f000 port 0xfeb4f200 irq 19
[ 2.735366] ata4: SATA max UDMA/133 abar m1024@0xfeb4f000 port 0xfeb4f280 irq 19
[ 2.759027] scsi4 : pata_atiixp
[ 2.759149] scsi5 : pata_atiixp
[ 2.759225] ata5: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0xf100 irq 14
[ 2.759230] ata6: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xf108 irq 15
[ 2.781140] r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded
[ 2.781169] r8169 0000:04:00.0: can't disable ASPM; OS doesn't have ASPM control
[ 2.781951] r8169 0000:04:00.0: irq 40 for MSI/MSI-X
[ 2.782365] r8169 0000:04:00.0 eth0: RTL8168evl/8111evl at 0xf8434000, 04:7d:7b:8b:72:22, XID 0c900800 IRQ 40
[ 2.782371] r8169 0000:04:00.0 eth0: jumbo features [frames: 9200 bytes, tx checksumming: ko]
[ 2.784254] rtsx_pci 0000:05:00.0: irq 41 for MSI/MSI-X
[ 2.784281] rtsx_pci 0000:05:00.0: rtsx_pci_acquire_irq: pcr->msi_en = 1, pci->irq = 41
[ 2.971914] usb 2-1: new high-speed USB device number 2 using ehci-pci
[ 3.051845] ata3: SATA link down (SStatus 0 SControl 300)
[ 3.051935] ata4: SATA link down (SStatus 0 SControl 300)
[ 3.106505] usb 2-1: New USB device found, idVendor=0bda, idProduct=8172
[ 3.106518] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 3.106528] usb 2-1: Product: RTL8191S WLAN Adapter
[ 3.106536] usb 2-1: Manufacturer: Manufacturer Realtek
[ 3.106544] usb 2-1: SerialNumber: 00e04c000001
[ 3.159761] tsc: Refined TSC clocksource calibration: 1596.599 MHz
[ 3.215764] usb 2-5: new high-speed USB device number 3 using ehci-pci
[ 3.223731] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 3.223778] ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[ 3.226112] ata2.00: ATA-8: WDC WD5000AAKX-083CA1, 19.01H19, max UDMA/100
[ 3.226124] ata2.00: 976773168 sectors, multi 16: LBA48 NCQ (depth 31/32), AA
[ 3.226826] ata1.00: ATAPI: PLDS DVD-RW DS8A8SH, KL31, max UDMA/100
[ 3.227833] ata1.00: configured for UDMA/100
[ 3.227898] ata2.00: configured for UDMA/100
[ 3.235655] scsi 0:0:0:0: CD-ROM PLDS DVD-RW DS8A8SH KL31 PQ: 0 ANSI: 5
[ 3.250664] sr0: scsi3-mmc drive: 24x/24x writer dvd-ram cd/rw xa/form2 cdda tray
[ 3.250674] cdrom: Uniform CD-ROM driver Revision: 3.20
[ 3.250960] sr 0:0:0:0: Attached scsi CD-ROM sr0
[ 3.251110] sr 0:0:0:0: Attached scsi generic sg0 type 5
[ 3.251417] scsi 1:0:0:0: Direct-Access ATA WDC WD5000AAKX-0 19.0 PQ: 0 ANSI: 5
[ 3.251797] sd 1:0:0:0: Attached scsi generic sg1 type 0
[ 3.251906] sd 1:0:0:0: [sda] 976773168 512-byte logical blocks: (500 GB/465 GiB)
[ 3.252179] sd 1:0:0:0: [sda] Write Protect is off
[ 3.252189] sd 1:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 3.252241] sd 1:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 3.340618] sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 sda9 >
[ 3.342410] sd 1:0:0:0: [sda] Attached SCSI disk
[ 3.373575] usb 2-5: New USB device found, idVendor=0ac8, idProduct=c42d
[ 3.373592] usb 2-5: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 3.373601] usb 2-5: Product: Lenovo USB 2.0 UVC Camera
[ 3.373610] usb 2-5: Manufacturer: Vimicro Corp.
[ 3.511609] usb 4-1: new low-speed USB device number 2 using ohci-pci
[ 3.709568] usb 4-1: New USB device found, idVendor=17ef, idProduct=602d
[ 3.709585] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 3.709595] usb 4-1: Product: Lenovo Black Silk USB Keyboard
[ 3.709603] usb 4-1: Manufacturer: Lenovo
[ 3.733197] hidraw: raw HID events driver (C) Jiri Kosina
[ 3.791962] usbcore: registered new interface driver usbhid
[ 3.791969] usbhid: USB HID core driver
[ 3.800502] input: Lenovo Lenovo Black Silk USB Keyboard as /devices/pci0000:00/0000:00:12.0/usb4/4-1/4-1:1.0/input/input11
[ 3.800675] hid-generic 0003:17EF:602D.0001: input,hidraw0: USB HID v1.11 Keyboard [Lenovo Lenovo Black Silk USB Keyboard] on usb-0000:00:12.0-1/input0
[ 3.807556] input: Lenovo Lenovo Black Silk USB Keyboard as /devices/pci0000:00/0000:00:12.0/usb4/4-1/4-1:1.1/input/input12
[ 3.807732] hid-generic 0003:17EF:602D.0002: input,hidraw1: USB HID v1.11 Device [Lenovo Lenovo Black Silk USB Keyboard] on usb-0000:00:12.0-1/input1
[ 3.855423] usb 4-5: new low-speed USB device number 3 using ohci-pci
[ 4.029389] usb 4-5: New USB device found, idVendor=04d9, idProduct=1133
[ 4.029406] usb 4-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 4.042976] input: HID 04d9:1133 as /devices/pci0000:00/0000:00:12.0/usb4/4-5/4-5:1.0/input/input13
[ 4.043269] hid-generic 0003:04D9:1133.0003: input,hidraw2: USB HID v1.10 Mouse [HID 04d9:1133] on usb-0000:00:12.0-5/input0
[ 4.159325] Switched to clocksource tsc
[ 5.912575] random: nonblocking pool is initialized
[ 9.476683] EXT4-fs (sda9): mounted filesystem with ordered data mode. Opts: (null)
[ 20.561732] Adding 1951740k swap on /dev/sda8. Priority:-1 extents:1 across:1951740k FS
[ 20.642098] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 20.834365] systemd-udevd[272]: starting version 204
[ 20.991413] lp: driver loaded but no devices found
[ 21.031664] ppdev: user-space parallel port driver
[ 21.105959] ACPI: Video Device [VGA1] (multi-head: yes rom: no post: no)