115k의 경우 미세하게 차이가 나지만...
라즈베리 파이 2라서 이정도 인데..
더 사양이 낮은걸로 가면 어떻게 되려나? 간격이 좁혀지려나? 궁금해지네..
나중에 PC에서도 해봐야겠다.
(빠르게 처리하고 출력이 느려서 발목잡히는거라면..
성능이 느린 녀석일수록 낮은 baud rate에서도 느려지지 않을 가능성이 높아 보이네..)
결론 : 시리얼 콘솔로 출력을 안하는게 미세하게라도 부팅을 빠르게 해준다.
단, 느리면 미친듯이 느려짐(ex 2400bps)
시리얼 콘솔 OFF
$ cat /boot/cmdline.txt dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
[ 5.538787] i2c /dev entries driver [ 8.942949] random: dd urandom read with 125 bits of entropy available [ 9.218847] random: nonblocking pool is initialized [ 9.239318] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup [ 10.899741] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 14.062018] cfg80211: Calling CRDA to update world regulatory domain [ 14.508474] Adding 102396k swap on /var/swap. Priority:-1 extents:2 across:2134012k SSFS [ 17.215920] cfg80211: Calling CRDA to update world regulatory domain |
시리얼 콘솔 115k
$ cat /boot/cmdline.txt dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
[ 6.610517] i2c /dev entries driver [ 8.755376] random: nonblocking pool is initialized [ 10.337207] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup [ 11.845371] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 15.171890] cfg80211: Calling CRDA to update world regulatory domain [ 15.575988] Adding 102396k swap on /var/swap. Priority:-1 extents:2 across:2134012k SSFS [ 18.323100] cfg80211: Calling CRDA to update world regulatory domain |
시리얼 콘솔 2.4k
$ cat /boot/cmdline.txt dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,2400 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
[ 65.375014] i2c /dev entries driver [ 69.878454] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup [ 71.466722] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 74.321086] cfg80211: Calling CRDA to update world regulatory domain [ 75.156305] Adding 102396k swap on /var/swap. Priority:-1 extents:2 across:2134012k SSFS [ 77.474999] cfg80211: Calling CRDA to update world regulatory domain |
+
시리얼 초기화에 시간이 이상하리 만치 오래 걸리고
확실히 메시지 출력에 시간소요 되는게 다르다.
115k - 0.004278초
[ 0.696002] console [ttyAMA0] enabled
[ 0.700280] bcm2835-mbox 3f00b880.mailbox: mailbox enabled
2.4k - 0.175674 초
[ 24.166507] console [ttyAMA0] enabled
[ 24.342181] bcm2835-mbox 3f00b880.mailbox: mailbox enabled
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2015.09.15
quiet 주면 로그가 출력이 거의 안되니까
부팅 시간에 영향을 거의 주지 않는다.
유의미한 부팅시간 차이는 없는 듯
no quiet / no console
$ cat /boot/cmdline.txt dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
$ dmesg [ 1.873744] smsc95xx v1.0.4 [ 1.941273] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:7c:e2:4e [ 2.158823] udevd[175]: starting version 175 [ 4.436091] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 4.657410] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 5.213253] fuse init (API version 7.23) [ 8.630851] random: dd urandom read with 121 bits of entropy available [ 9.128626] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup [ 9.533223] random: nonblocking pool is initialized [ 10.676478] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 11.380752] Adding 102396k swap on /var/swap. Priority:-1 extents:2 across:2134012k SSFS |
quiet / 2400bps
$ cat /boot/cmdline.txt dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,2400 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait quiet
$ dmesg [ 1.787155] smsc95xx v1.0.4 [ 1.849754] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:7c:e2:4e [ 2.159625] udevd[175]: starting version 175 [ 4.475902] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 4.687585] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 5.243639] fuse init (API version 7.23) [ 8.657857] random: dd urandom read with 122 bits of entropy available [ 9.236423] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup [ 9.285362] random: nonblocking pool is initialized [ 10.784245] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 11.661120] Adding 102396k swap on /var/swap. Priority:-1 extents:2 across:2134012k SSFS |
quiet / 115k
$ cat /boot/cmdline.txt dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait quiet
$ dmesg [ 1.787064] smsc95xx v1.0.4 [ 1.848037] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:7c:e2:4e [ 2.083949] udevd[175]: starting version 175 [ 4.375384] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 4.588231] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 5.138807] fuse init (API version 7.23) [ 8.506983] random: dd urandom read with 123 bits of entropy available [ 9.087136] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup [ 9.132055] random: nonblocking pool is initialized [ 10.595072] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 11.272396] Adding 102396k swap on /var/swap. Priority:-1 extents:2 across:2134012k SSFS |
[링크 : http://elinux.org/Disable_Console]
[링크 : https://www.kernel.org/doc/Documentation/kernel-parameters.txt]
+
2015.09.16
라즈베리 B에서 테스트
2400bps로 설정하면 라즈베리 B나 2B나 부팅시간이 거의 동일해진다 ㄷㄷ
# cat /flash/cmdline.txt
boot=/dev/mmcblk0p1 disk=/dev/mmcblk0p2 quiet
[ 6.260069] lirc_rpi: auto-detected active low receiver on GPIO pin 18
[ 6.260446] lirc_rpi lirc_rpi.0: lirc_dev: driver lirc_rpi registered at minor = 0
[ 6.260465] lirc_rpi: driver registered!
[ 9.116106] Console: switching to colour dummy device 80x30
[ 10.033464] pcm512x 1-004d: Failed to reset device: -5
[ 10.033606] pcm512x: probe of 1-004d failed with error -5
[ 10.038823] pcm512x 1-004c: Failed to reset device: -5
[ 10.038972] pcm512x: probe of 1-004c failed with error -5
[ 11.996185] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
[ 11.996923] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 13.503507] input: lircd as /devices/virtual/input/input0
[ 13.513621] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
[ 13.543861] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
# cat /flash/cmdline.txt
boot=/dev/mmcblk0p1 disk=/dev/mmcblk0p2 console=ttyAMA0,115200
[ 7.583641] lirc_rpi: auto-detected active low receiver on GPIO pin 18
[ 7.584050] lirc_rpi lirc_rpi.0: lirc_dev: driver lirc_rpi registered at minor = 0
[ 7.584073] lirc_rpi: driver registered!
[ 7.590570] systemd[1]: Reached target Local File Systems.
[ 7.590980] systemd[1]: Started Rebuild Journal Catalog.
[ 7.607263] systemd[1]: Started Load Kernel Modules.
[ 7.673956] systemd[1]: Started Journal Service.
[ 7.835377] systemd-journald[149]: Received request to flush runtime journal from PID 1
[ 11.254985] Console: switching to colour dummy device 80x30
[ 12.137394] pcm512x 1-004d: Failed to reset device: -5
[ 12.137547] pcm512x: probe of 1-004d failed with error -5
[ 12.142543] pcm512x 1-004c: Failed to reset device: -5
[ 12.142698] pcm512x: probe of 1-004c failed with error -5
[ 14.273315] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
[ 14.276243] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 15.827031] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
[ 15.861468] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 15.930351] input: lircd as /devices/virtual/input/input0
# cat /flash/cmdline.txt
boot=/dev/mmcblk0p1 disk=/dev/mmcblk0p2 console=ttyAMA0,2400
[ 59.096555] lirc_rpi: auto-detected active low receiver on GPIO pin 18
[ 59.096935] lirc_rpi lirc_rpi.0: lirc_dev: driver lirc_rpi registered at minor = 0
[ 59.096958] lirc_rpi: driver registered!
[ 59.253490] systemd[1]: Mounted Temporary Directory.
[ 59.530181] systemd[1]: Started Remount Root and Kernel File Systems.
[ 59.910190] systemd[1]: Started Create list of required static device nodes for the current kernel.
[ 60.106840] systemd[1]: Started Setup machine-id.
[ 60.323515] systemd[1]: Started Set ondemand threshold.
[ 60.500170] systemd[1]: Started Show Version.
[ 60.716824] systemd[1]: Started Load Kernel Modules.
[ 60.950148] systemd[1]: Started Kodi config dir rebrand.
[ 61.146860] systemd[1]: Started Mounting swapfile.
[ 61.376843] systemd[1]: Started udev Coldplug all Devices.
[ 61.848866] systemd[1]: Starting Swap.
[ 62.016818] systemd[1]: Reached target Swap.
[ 62.017203] systemd[1]: Mounted FUSE Control File System.
[ 62.018077] systemd[1]: Mounted Configuration File System.
[ 62.018331] systemd[1]: Starting Apply Kernel Variables...
[ 62.213534] systemd[1]: Starting Journal Service...
[ 62.377729] systemd[1]: Starting Create Static Device Nodes in /dev...
[ 62.620386] systemd[1]: Starting Setup Timezone data...
[ 62.804543] systemd[1]: Started Debug /var/log relink.
[ 63.003508] systemd[1]: Started Journal Service.
[ 64.752792] systemd-journald[160]: Received request to flush runtime journal from PID 1
[ 69.797632] pcm512x 1-004d: Failed to reset device: -5
[ 69.797788] pcm512x: probe of 1-004d failed with error -5
[ 69.802172] pcm512x 1-004c: Failed to reset device: -5
[ 69.802323] pcm512x: probe of 1-004c failed with error -5
[ 71.876799] Console: switching to colour dummy device 80x30
[ 75.422833] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
[ 75.425714] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 76.986887] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
[ 76.995598] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 78.083255] input: lircd as /devices/virtual/input/input0