我对 Debian 系统 (jessie/sid) 进行了全面升级。不幸的是现在启动时有 30 秒的间隙，我真的不知道它从哪里来，也不知道我必须在哪里找到它。
我看了看/var/log/dmesg，发现了一些有趣的台词。注意27.280227和之间的差距56.835253。
[ 27.261104] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[ 27.280207] cfg80211: World regulatory domain updated:
[ 27.280213] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[ 27.280216] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm)
[ 27.280218] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm)
[ 27.280220] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm)
[ 27.280223] cfg80211: (5170000 KHz - 5250000 KHz @ 80000 KHz), (N/A, 2000 mBm)
[ 27.280225] cfg80211: (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm)
[ 27.280227] cfg80211: (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm)
[ 27.843406] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off
[ 56.835253] EXT4-fs (dm-1): re-mounted. Opts: (null)
[ 57.068560] EXT4-fs (dm-1): re-mounted. Opts: errors=remount-ro
[ 57.615554] lp: driver loaded but no devices found
[ 57.661815] ppdev: user-space parallel port driver
[ 57.855124] fuse init (API version 7.22)
[ 58.123866] Adding 4886524k swap on /dev/mapper/encrypted-swap. Priority:-1 extents:1 across:4886524k
[ 58.327537] EXT4-fs (sda4): mounted filesystem with ordered data mode. Opts: (null)
[ 59.137990] RPC: Registered named UNIX socket transport module.
[ 59.137996] RPC: Registered udp transport module.
[ 59.137998] RPC: Registered tcp transport module.
[ 59.138000] RPC: Registered tcp NFSv4.1 backchannel transport module.
搜索[drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off指向一些图形错误。由于我的显卡（可切换显卡）有时会出现问题，这可能是一个原因。
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
Subsystem: Dell Device 04cd
Flags: bus master, fast devsel, latency 0, IRQ 52
Memory at f6400000 (64-bit, non-prefetchable) [size=4M]
Memory at d0000000 (64-bit, prefetchable) [size=256M]
I/O ports at f000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [a4] PCI Advanced Features
Kernel driver in use: i915
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Whistler [Radeon HD 6630M/6650M/6750M/7670M/7690M] (prog-if 00 [VGA controller])
Subsystem: Dell Radeon HD 6630M
Flags: bus master, fast devsel, latency 0, IRQ 53
Memory at e0000000 (64-bit, prefetchable) [size=256M]
Memory at f7b20000 (64-bit, non-prefetchable) [size=128K]
I/O ports at e000 [size=256]
Expansion ROM at f7b00000 [disabled] [size=128K]
Capabilities: [50] Power Management version 3
Capabilities: [58] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Kernel driver in use: fglrx_pci
正如我所说，我不知道该在哪里查看和搜索什么。我也很高兴看到一些可能有帮助的关键字。
我希望我提供了您需要的信息。如果没有，如果您也可以告诉我必须执行哪个命令才能获得您想要的输出，那就太好了，因为我仍然不太熟悉“更深层次的系统”。
非常感谢，
罗科
答案1
如果你不使用systemd，它可能是udev 中的 Debian 错误 754987，因为它涉及 30 秒的延迟。
我的 dmesg 日志文件中此错误的后果：
[ 19.809738] input: HP WMI hotkeys as /devices/virtual/input/input14
[ 25.107974] WARNING! power/level is deprecated; use power/control instead
[ 50.739902] Adding 19800076k swap on /dev/sda5. Priority:-1 extents:1 across:19800076k FS
[ 50.780205] EXT4-fs (sda1): re-mounted. Opts: (null)
[ 51.259666] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro
[ 52.346718] lp: driver loaded but no devices found
[ 52.469463] loop: module loaded
[ 52.491077] smsc47b397: found SMSC SCH5317 (base address 0x0480, revision 1)
[ 52.538276] fuse init (API version 7.23)
它看起来和你的很相似。