我正在运行 Ubuntu 20.04.5 LTS 并使用 gnome-classic 桌面（因为我坚持自己的方式）。当我最初登录时，我总是注意到 dbus-daemon 占用了几分钟的高 CPU，但它总是会稳定到可接受的水平。然而，在过去的几天里，dbus-daemon 和 system-udevd 一直占 CPU 的 50%，并且在笔记本电脑运行时没有稳定下来，导致风扇不断运行。
我运行了dbus-monitor --system一个非常快速的消息假脱机运行，如下面的摘录：
signal time=1676894325.355898 sender=org.freedesktop.DBus -> destination=:1.245 serial=2 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
string ":1.245"
signal time=1676894325.365912 sender=:1.1 -> destination=(null destination) serial=4880989 path=/org/freedesktop/systemd1/unit/sys_2ddevices_2dvirtual_2dblock_2ddm_5cx2d2_2edevice; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
string "org.freedesktop.systemd1.Device"
array [
dict entry(
string "SysFSPath"
variant string "/sys/devices/virtual/block/dm-2"
)
]
array [
]
signal time=1676894325.366042 sender=:1.1 -> destination=(null destination) serial=4880990 path=/org/freedesktop/systemd1/unit/sys_2ddevices_2dvirtual_2dblock_2ddm_5cx2d2_2edevice; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
string "org.freedesktop.systemd1.Unit"
array [
dict entry(
string "ActiveState"
variant string "active"
)
dict entry(
string "SubState"
variant string "plugged"
)
dict entry(
string "StateChangeTimestamp"
variant uint64 1676892339266329
)
dict entry(
string "StateChangeTimestampMonotonic"
variant uint64 19734942
)
dict entry(
string "InactiveExitTimestamp"
variant uint64 1676892339266329
)
dict entry(
string "InactiveExitTimestampMonotonic"
variant uint64 19734942
)
dict entry(
string "ActiveEnterTimestamp"
variant uint64 1676892339266329
)
dict entry(
string "ActiveEnterTimestampMonotonic"
variant uint64 19734942
)
dict entry(
string "ActiveExitTimestamp"
variant uint64 0
)
dict entry(
string "ActiveExitTimestampMonotonic"
variant uint64 0
)
dict entry(
string "InactiveEnterTimestamp"
variant uint64 0
)
dict entry(
string "InactiveEnterTimestampMonotonic"
variant uint64 0
)
dict entry(
string "Job"
variant struct {
uint32 0
object path "/"
}
)
dict entry(
string "ConditionResult"
variant boolean false
)
dict entry(
string "AssertResult"
variant boolean false
)
dict entry(
string "ConditionTimestamp"
variant uint64 0
)
dict entry(
string "ConditionTimestampMonotonic"
variant uint64 0
)
dict entry(
string "AssertTimestamp"
variant uint64 0
)
dict entry(
string "AssertTimestampMonotonic"
variant uint64 0
)
dict entry(
string "InvocationID"
variant array of bytes [
4c 6f ff 28 3e 58 4e 6e 81 82 b3 1c 0c 83 82 3b
]
)
]
array [
string "Conditions"
string "Asserts"
]
signal time=1676894325.366191 sender=:1.1 -> destination=(null destination) serial=4880991 path=/org/freedesktop/systemd1/unit/dev_2ddm_5cx2d2_2edevice; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
string "org.freedesktop.systemd1.Device"
array [
dict entry(
string "SysFSPath"
variant string "/sys/devices/virtual/block/dm-2"
)
]
array [
]
signal time=1676894325.366431 sender=:1.1 -> destination=(null destination) serial=4880992 path=/org/freedesktop/systemd1/unit/dev_2ddm_5cx2d2_2edevice; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
string "org.freedesktop.systemd1.Unit"
array [
dict entry(
string "ActiveState"
variant string "active"
)
dict entry(
string "SubState"
variant string "plugged"
)
dict entry(
string "StateChangeTimestamp"
variant uint64 1676892339266328
)
dict entry(
string "StateChangeTimestampMonotonic"
variant uint64 19734941
)
dict entry(
string "InactiveExitTimestamp"
variant uint64 1676892339266328
)
dict entry(
string "InactiveExitTimestampMonotonic"
variant uint64 19734941
)
dict entry(
string "ActiveEnterTimestamp"
variant uint64 1676892339266328
)
dict entry(
string "ActiveEnterTimestampMonotonic"
variant uint64 19734941
)
dict entry(
string "ActiveExitTimestamp"
variant uint64 0
)
dict entry(
string "ActiveExitTimestampMonotonic"
variant uint64 0
)
dict entry(
string "InactiveEnterTimestamp"
variant uint64 0
)
dict entry(
string "InactiveEnterTimestampMonotonic"
variant uint64 0
)
dict entry(
string "Job"
variant struct {
uint32 0
object path "/"
}
)
dict entry(
string "ConditionResult"
variant boolean false
)
dict entry(
string "AssertResult"
variant boolean false
)
dict entry(
string "ConditionTimestamp"
variant uint64 0
)
dict entry(
string "ConditionTimestampMonotonic"
variant uint64 0
)
dict entry(
string "AssertTimestamp"
variant uint64 0
)
dict entry(
string "AssertTimestampMonotonic"
variant uint64 0
)
dict entry(
string "InvocationID"
variant array of bytes [
0c b8 d1 90 42 3e 45 b6 88 f3 71 6e 66 1e 83 c5
]
)
]
array [
string "Conditions"
string "Asserts"
]
运行udevadm monitor给出了类似的消息流，虽然不是那么快，如下所示：
KERNEL[2188.932041] change /devices/virtual/block/dm-2 (block)
UDEV [2188.940914] change /devices/virtual/block/dm-2 (block)
KERNEL[2188.945441] change /devices/virtual/block/dm-2 (block)
UDEV [2188.957689] change /devices/virtual/block/dm-2 (block)
KERNEL[2188.961225] change /devices/virtual/block/dm-2 (block)
UDEV [2188.969813] change /devices/virtual/block/dm-2 (block)
KERNEL[2188.974779] change /devices/virtual/block/dm-2 (block)
dm-2显然是出于某种原因。 dm-2是我的主分区：
~$ ls -l /dev/mapper/
total 0
crw------- 1 root root 10, 236 Feb 20 11:25 control
lrwxrwxrwx 1 root root 7 Feb 20 12:02 home -> ../dm-2
lrwxrwxrwx 1 root root 7 Feb 20 11:25 sda3_crypt -> ../dm-0
lrwxrwxrwx 1 root root 7 Feb 20 11:25 swap -> ../dm-1
我对 dbus 和 udev 的理解至少可以说是有限的，但是一些谷歌搜索让我看到了这篇文章，该文章建议我创建一个文件/etc/udev/rulesd/90-fixdm.rules，其中包含
ACTION=="add|change", KERNEL=="dm-*", OPTIONS:="nowatch"
这确实立即使这两个进程平静下来并恢复了我的 CPU 周期（并阻止笔记本电脑风扇持续运行）。然而，第二天笔记本电脑无法启动，挂在一个永远不会启动的“等待/dev/mapper/swap”作业上。一个惊慌失措的使用 Live-Ubuntu 棒从稍后删除文件/etc/udev/rulesd/90-fixdm.rules，我回到原点 - 笔记本电脑再次启动，但高 CPU 使用率已经dbus-daemon恢复system-udevd。
可能发生了什么变化导致了这种新行为，我该怎么做才能解决这个问题？
谢谢。
