我正在运行 Ubuntu Desktop，我注意到 systemd 会定期消耗大量 CPU。这种情况似乎是定期发生的，没有任何明显的触发因素。过去，当我重新启动机器时，问题就消失了，但我想了解为什么会发生这种情况。我曾经strace调查过，发现当 CPU 使用率变高时（我通过 CPU 风扇的声音知道这一点），会进行不同的调用newfstatat，其中一些调用会出现错误（“找不到文件”）。有人可以提供一些关于如何诊断和修复此问题的指导吗？
编辑：
systemd 版本：
systemd 251 (251.4-1ubuntu7.3)
+PAM +AUDIT +SELINUX +APPARMOR +IMA +SMACK +SECCOMP +GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY -P11KIT -QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK -XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified
$ sudo strace -c -p 2268
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
100,00 0,000001 0 56 34 newfstatat
0,00 0,000000 0 8 close
0,00 0,000000 0 4 recvmsg
0,00 0,000000 0 7 gettid
0,00 0,000000 0 6 epoll_wait
0,00 0,000000 0 4 pipe2
0,00 0,000000 0 40 getrandom
------ ----------- ----------- --------- --------- ----------------
100,00 0,000001 0 125 34 total
$ sudo strace -fvttTyy -p 2268
strace: Process 2268 attached
14:40:14.635234 gettid() = 2268 <0.000017>
14:40:14.635365 epoll_wait(4<anon_inode:[eventpoll]>, [{events=EPOLLIN, data={u32=2321867760, u64=94577501725680}}], 86, -1) = 1 <22.626761>
14:40:37.262325 recvmsg(15<NETLINK:[KOBJECT_UEVENT:2268]>, {msg_name={sa_family=AF_NETLINK, nl_pid=308024, nl_groups=0x000002}, msg_namelen=128 => 12, msg_iov=[{iov_base=[{prefix="libudev", magic=htonl(0xfeedcafe), header_size=40, properties_off=40, properties_len=947, filter_subsystem_hash=htonl(0xf0031db7), filter_devtype_hash=htonl(0x7bcbc5ee), filter_tag_bloom_hi=htonl(0x2000400), filter_tag_bloom_lo=htonl(0x10800000)}, "UDEV_DATABASE_VERSION=1\0ACTION=c"...], iov_len=8192}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=356244, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, 0) = 987 <0.000064>
14:40:37.263883 getrandom("\x9b\xd1\x64\x37\x24\x2f\x36\xfe\x59\x7b\x32\x6d\x08\x97\x2b\xce", 16, GRND_INSECURE) = 16 <0.000055>
14:40:37.264086 getrandom("\xe6\x88\x2a\xe3\xc8\xe9\x62\x15\x83\xf2\x27\xc9\x70\xf1\x2f\xc3", 16, GRND_INSECURE) = 16 <0.000051>
14:40:37.264248 getrandom("\x63\x14\xa7\xc9\x5f\xe6\x60\xb5\xf2\xcd\xdc\x1b\x22\xe0\x91\xfb", 16, GRND_INSECURE) = 16 <0.000051>
14:40:37.264452 pipe2([22<pipe:[3287284]>, 23<pipe:[3287284]>], O_NONBLOCK|O_CLOEXEC) = 0 <0.000073>
14:40:37.264657 pipe2([24<pipe:[3287286]>, 25<pipe:[3287286]>], O_NONBLOCK|O_CLOEXEC) = 0 <0.000057>
14:40:37.264860 getrandom("\x78\xc5\xf6\xfd\x29\xa3\x15\x9a\x7f\x53\xec\x31\xad\x9e\x7c\xc5", 16, GRND_INSECURE) = 16 <0.000052>
14:40:37.265038 getrandom("\xed\x43\xba\x70\xef\x28\x9a\x3f\x01\x1c\x39\xcc\x51\x4e\x89\xa3", 16, GRND_INSECURE) = 16 <0.000052>
14:40:37.265277 getrandom("\x96\x15\xc3\xb0\x46\x67\xef\x77\x4a\x9c\xe3\x18\xb8\xf5\xb4\x33", 16, GRND_INSECURE) = 16 <0.000049>
14:40:37.265591 getrandom("\x59\x7f\x23\xeb\x76\xea\x81\x82\xed\x4b\x01\x8e\xe5\xfa\x7d\x5c", 16, GRND_INSECURE) = 16 <0.000063>
14:40:37.266157 getrandom("\x7b\xae\xc6\x5c\x39\x01\x37\x03\x35\xc1\xbf\x89\xd8\xf4\x33\x5d", 16, GRND_INSECURE) = 16 <0.000055>
14:40:37.267407 getrandom("\x8b\xf7\x9d\x77\xe7\xfc\x49\x29\xbc\x92\xad\xac\xfb\x80\xe3\x8f", 16, GRND_INSECURE) = 16 <0.000067>
14:40:37.269564 getrandom("\x01\x44\x07\xa8\x8e\xf6\xc5\xe1\xd3\xd4\xf6\x46\x37\x2e\xe8\x44", 16, GRND_INSECURE) = 16 <0.000029>
14:40:37.277204 getrandom("\x89\xa6\xdc\x1f\x5e\xd6\x74\xab\x3b\x3b\x3a\x48\xcb\x6c\xcc\x5f", 16, GRND_INSECURE) = 16 <0.000021>
14:40:37.310595 getrandom("\x38\x40\x5e\x95\xfc\xff\x5e\x76\xda\xc0\x24\x13\x58\xcf\x04\xdb", 16, GRND_INSECURE) = 16 <0.000027>
14:40:37.402512 getrandom("\x70\x25\x9d\x31\x15\xa2\xbe\x60\x35\x96\x5f\x64\x3f\xd8\xd1\x53", 16, GRND_INSECURE) = 16 <0.000056>
14:40:37.748203 getrandom("\x26\x6d\xb2\x58\x07\xe4\x11\x14\xd1\x10\xe3\x11\xbd\x23\x8d\xce", 16, GRND_INSECURE) = 16 <0.000179>
14:40:39.005297 getrandom("\xb5\xf0\xee\x04\x5f\x6f\x84\x7b\x57\x69\x9e\x81\xb9\xf2\x04\xb4", 16, GRND_INSECURE) = 16 <0.000138>
14:40:41.050125 newfstatat(AT_FDCWD</>, "/dev/disk/by-path/pci-0000:00:1d.0-usb-0:1.6:1.0-scsi-0:0:0:0", {st_dev=makedev(0, 0x5), st_ino=363, st_mode=S_IFBLK|0660, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(0x8, 0x10), st_atime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_atime_nsec=277691097, st_mtime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_mtime_nsec=277691097, st_ctime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_ctime_nsec=277691097}, 0) = 0 <0.000221>
14:40:41.050959 newfstatat(AT_FDCWD</>, "/dev/disk/by-id/usb-Generic-_Multi-Card_20090516388200000-0:0", {st_dev=makedev(0, 0x5), st_ino=363, st_mode=S_IFBLK|0660, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(0x8, 0x10), st_atime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_atime_nsec=277691097, st_mtime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_mtime_nsec=277691097, st_ctime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_ctime_nsec=277691097}, 0) = 0 <0.000044>
14:40:41.051148 newfstatat(AT_FDCWD</>, "/dev/disk/by-diskseq/18086", 0x7fff5c2fe760, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000061>
14:40:41.051926 newfstatat(AT_FDCWD</>, "/home/ubuntu/.config/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000168>
14:40:41.052538 newfstatat(AT_FDCWD</>, "/etc/xdg/systemd/user", {st_dev=makedev(0x8, 0x1), st_ino=18352495, st_mode=S_IFDIR|0755, st_nlink=7, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=4096, st_atime=1681357107 /* 2023-04-13T04:38:27.861624256+0100 */, st_atime_nsec=861624256, st_mtime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_mtime_nsec=407382145, st_ctime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_ctime_nsec=407382145}, 0) = 0 <0.000122>
14:40:41.052968 newfstatat(AT_FDCWD</>, "/etc/systemd/user", {st_dev=makedev(0x8, 0x1), st_ino=18352495, st_mode=S_IFDIR|0755, st_nlink=7, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=4096, st_atime=1681357107 /* 2023-04-13T04:38:27.861624256+0100 */, st_atime_nsec=861624256, st_mtime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_mtime_nsec=407382145, st_ctime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_ctime_nsec=407382145}, 0) = 0 <0.000023>
14:40:41.053169 newfstatat(AT_FDCWD</>, "/run/user/1000/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000039>
14:40:41.053280 newfstatat(AT_FDCWD</>, "/run/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000038>
14:40:41.053397 newfstatat(AT_FDCWD</>, "/home/ubuntu/.local/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000033>
14:40:41.053505 newfstatat(AT_FDCWD</>, "/var/lib/flatpak/exports/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000020>
14:40:41.053650 newfstatat(AT_FDCWD</>, "/usr/local/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000015>
14:40:41.053729 newfstatat(AT_FDCWD</>, "/usr/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000018>
14:40:41.053819 newfstatat(AT_FDCWD</>, "/usr/local/lib/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000031>
14:40:41.053912 newfstatat(AT_FDCWD</>, "/usr/lib/systemd/user", {st_dev=makedev(0x8, 0x1), st_ino=8259220, st_mode=S_IFDIR|0755, st_nlink=14, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=48, st_size=20480, st_atime=1681357107 /* 2023-04-13T04:38:27.861624256+0100 */, st_atime_nsec=861624256, st_mtime=1681357099 /* 2023-04-13T04:38:19.600985446+0100 */, st_mtime_nsec=600985446, st_ctime=1681357099 /* 2023-04-13T04:38:19.600985446+0100 */, st_ctime_nsec=600985446}, 0) = 0 <0.000021>
14:40:41.054513 getrandom("\x7d\xe1\x15\xfa\x80\xf6\xc4\xeb\x30\xff\xe1\x1a\x32\x1e\xd8\x1c", 16, GRND_INSECURE) = 16 <0.000013>
14:40:41.058269 gettid() = 2268 <0.000016>
14:40:41.058360 epoll_wait(4<anon_inode:[eventpoll]>, [{events=EPOLLIN, data={u32=2321867760, u64=94577501725680}}], 86, 0) = 1 <0.000041>
14:40:41.058501 recvmsg(15<NETLINK:[KOBJECT_UEVENT:2268]>, {msg_name={sa_family=AF_NETLINK, nl_pid=308024, nl_groups=0x000002}, msg_namelen=128 => 12, msg_iov=[{iov_base=[{prefix="libudev", magic=htonl(0xfeedcafe), header_size=40, properties_off=40, properties_len=947, filter_subsystem_hash=htonl(0xf0031db7), filter_devtype_hash=htonl(0x7bcbc5ee), filter_tag_bloom_hi=htonl(0x2000400), filter_tag_bloom_lo=htonl(0x10800000)}, "UDEV_DATABASE_VERSION=1\0ACTION=c"...], iov_len=8192}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=356244, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, 0) = 987 <0.000022>
14:40:41.058701 getrandom("\x80\x1d\x29\x7d\x8b\x2e\x72\xd8\x5d\x7b\xe6\x05\xd5\xb9\x02\xcc", 16, GRND_INSECURE) = 16 <0.000016>
14:40:41.058790 getrandom("\x23\xff\x23\x09\x75\xf1\x58\x97\xf7\xe3\xbf\x89\x57\x27\x65\x44", 16, GRND_INSECURE) = 16 <0.000011>
14:40:41.058905 getrandom("\x89\xe9\x02\x45\x62\x60\x97\x26\x1c\x1a\x20\x9a\xe0\xd5\x18\xc3", 16, GRND_INSECURE) = 16 <0.000012>
14:40:48.480425 newfstatat(AT_FDCWD</>, "/dev/disk/by-path/pci-0000:00:1d.0-usb-0:1.6:1.0-scsi-0:0:0:0", {st_dev=makedev(0, 0x5), st_ino=363, st_mode=S_IFBLK|0660, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(0x8, 0x10), st_atime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_atime_nsec=277691097, st_mtime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_mtime_nsec=277691097, st_ctime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_ctime_nsec=277691097}, 0) = 0 <0.000216>
14:40:48.481153 newfstatat(AT_FDCWD</>, "/dev/disk/by-id/usb-Generic-_Multi-Card_20090516388200000-0:0", {st_dev=makedev(0, 0x5), st_ino=363, st_mode=S_IFBLK|0660, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(0x8, 0x10), st_atime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_atime_nsec=277691097, st_mtime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_mtime_nsec=277691097, st_ctime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_ctime_nsec=277691097}, 0) = 0 <0.000053>
14:40:48.481384 newfstatat(AT_FDCWD</>, "/dev/disk/by-diskseq/18087", {st_dev=makedev(0, 0x5), st_ino=363, st_mode=S_IFBLK|0660, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(0x8, 0x10), st_atime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_atime_nsec=277691097, st_mtime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_mtime_nsec=277691097, st_ctime=1681479637 /* 2023-04-14T14:40:37.277691097+0100 */, st_ctime_nsec=277691097}, 0) = 0 <0.000065>
14:40:48.481599 newfstatat(AT_FDCWD</>, "/home/ubuntu/.config/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000043>
14:40:48.481703 newfstatat(AT_FDCWD</>, "/etc/xdg/systemd/user", {st_dev=makedev(0x8, 0x1), st_ino=18352495, st_mode=S_IFDIR|0755, st_nlink=7, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=4096, st_atime=1681357107 /* 2023-04-13T04:38:27.861624256+0100 */, st_atime_nsec=861624256, st_mtime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_mtime_nsec=407382145, st_ctime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_ctime_nsec=407382145}, 0) = 0 <0.000047>
14:40:48.481829 newfstatat(AT_FDCWD</>, "/etc/systemd/user", {st_dev=makedev(0x8, 0x1), st_ino=18352495, st_mode=S_IFDIR|0755, st_nlink=7, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=4096, st_atime=1681357107 /* 2023-04-13T04:38:27.861624256+0100 */, st_atime_nsec=861624256, st_mtime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_mtime_nsec=407382145, st_ctime=1677139713 /* 2023-02-23T09:08:33.407382145+0100 */, st_ctime_nsec=407382145}, 0) = 0 <0.000041>
14:40:48.481936 newfstatat(AT_FDCWD</>, "/run/user/1000/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000060>
14:40:48.482063 newfstatat(AT_FDCWD</>, "/run/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000023>
14:40:48.482138 newfstatat(AT_FDCWD</>, "/home/ubuntu/.local/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000072>
14:40:48.482267 newfstatat(AT_FDCWD</>, "/var/lib/flatpak/exports/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000036>
14:40:48.482363 newfstatat(AT_FDCWD</>, "/usr/local/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000019>
14:40:48.482453 newfstatat(AT_FDCWD</>, "/usr/share/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000013>
14:40:48.482529 newfstatat(AT_FDCWD</>, "/usr/local/lib/systemd/user", 0x7fff5c2fe3a0, 0) = -1 ENOENT (Aucun fichier ou dossier de ce type) <0.000019>
14:40:48.482615 newfstatat(AT_FDCWD</>, "/usr/lib/systemd/user", {st_dev=makedev(0x8, 0x1), st_ino=8259220, st_mode=S_IFDIR|0755, st_nlink=14, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=48, st_size=20480, st_atime=1681357107 /* 2023-04-13T04:38:27.861624256+0100 */, st_atime_nsec=861624256, st_mtime=1681357099 /* 2023-04-13T04:38:19.600985446+0100 */, st_mtime_nsec=600985446, st_ctime=1681357099 /* 2023-04-13T04:38:19.600985446+0100 */, st_ctime_nsec=600985446}, 0) = 0 <0.000017>
14:40:48.483185 getrandom("\x93\xf8\x80\xf8\xaa\xc4\x0a\x50\x17\x69\xb1\x12\xd1\x21\x5d\xb0", 16, GRND_INSECURE) = 16 <0.000034>
14:40:48.487005 gettid() = 2268 <0.000018>
14:40:48.487095 epoll_wait(4<anon_inode:[eventpoll]>, [], 86, 0) = 0 <0.000069>
14:40:48.630122 close(22<pipe:[3287284]>) = 0 <0.000142>
14:40:48.630574 close(23<pipe:[3287284]>) = 0 <0.000055>
14:40:48.630738 close(24<pipe:[3287286]>) = 0 <0.000019>
14:40:48.630818 close(25<pipe:[3287286]>) = 0 <0.000022>
14:40:48.630906 gettid() = 2268 <0.000013>
14:40:48.630973 epoll_wait(4<anon_inode:[eventpoll]>, ^Cstrace: Process 2268 detached
<detached ...>
谢谢。