Just upgraded to ubuntu 20.04
gnome-shell is sitting continually at around 20% CPU usage.
Any help? some details below:
top - 15:01:14 up 48 min, 1 user, load average: 0.16, 0.63, 0.76
Tasks: 397 total, 1 running, 396 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.2 us, 0.3 sy, 0.0 ni, 97.3 id, 0.0 wa, 0.0 hi, 0.1 si, 0.0 st
MiB Mem : 32015.4 total, 17153.7 free, 2707.2 used, 12154.5 buff/cache
MiB Swap: 32668.0 total, 32668.0 free, 0.0 used. 28748.7 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2709 alan 20 0 4588528 550700 124664 S 21.2 1.7 8:55.91 gnome-shell
Looking at what it is doing it seems to spend most time stat-ing files that dont exist:
strace -C -p 2709
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
54.40 0.233348 2 95108 90024 stat
10.72 0.045978 3 12340 10326 recvmsg
7.39 0.031684 4 7780 getpid
7.20 0.030878 5 5875 poll
3.84 0.016474 5 2796 writev
3.38 0.014505 15 942 ioctl
2.53 0.010840 2 4340 1550 openat
1.89 0.008100 2 3100 getdents64
1.81 0.007768 3 2198 read
1.33 0.005718 1 2869 close
1.32 0.005682 4 1301 90 futex
1.17 0.005004 1 2790 fstat
1.01 0.004339 3 1244 sched_yield
0.63 0.002720 5 538 write
0.58 0.002469 3 764 mprotect
0.43 0.001845 3 511 mmap
0.36 0.001540 2 640 munmap
0.00 0.000021 4 5 recvfrom
0.00 0.000013 1 11 clock_nanosleep
0.00 0.000003 3 1 restart_syscall
0.00 0.000001 0 4 getrusage
------ ----------- ----------- --------- --------- ----------------
100.00 0.428930 145157 101990 total
And some output from strace (edited):
...
stat("/home/alan/.local/share/icons/hicolor/16x16@2/apps", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/apps", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/categories", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/categories", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/categories", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/categories", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/devices", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/devices", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/devices", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/devices", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/emblems", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/emblems", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/emblems", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/emblems", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/emotes", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16/emotes", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
stat("/home/alan/.local/share/icons/hicolor/16x16@2/emotes", 0x7ffc14b2b2f0) = -1 ENOENT (No such file or directory)
...
getpid() = 2709
getpid() = 2709
getpid() = 2709
getpid() = 2709
getpid() = 2709
getpid() = 2709
ioctl(12, _IOC(_IOC_READ|_IOC_WRITE, 0x46, 0x2a, 0x20), 0x7ffc14b2d780) = 0
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="\31\0\v\0\367\212\240\2\0\0\0\0! \0\0\367\212\240\2\336\1\0\0006\r\0\0\0\0\0\0"..., iov_len=44}, {iov_base=NULL, iov_len=0}, {iov_base="", iov_len=0}], 3) = 44
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="\206\20\2\0.\0\340\0\206\t\5\0000\0\340\0\4\0\0\0\0\0\0\0\236\3\0\0\206\3\4\0"..., iov_len=44}, {iov_base=NULL, iov_len=0}, {iov_base="", iov_len=0}], 3) = 44
recvmsg(31, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="T\1&\0360\0\340\0\0\0\0\0\236\3\0\0\0\0\0\0\236\3\0\0:\t#\0\0\0\0\0", iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=27, events=POLLIN}, {fd=28, events=POLLIN}, {fd=29, events=POLLIN}, {fd=31, events=POLLIN}, {fd=32, events=POLLIN}, {fd=34, events=POLLIN}, {fd=35, events=POLLIN}, {fd=41, events=POLLIN}, {fd=46, events=POLLIN}, {fd=50, events=POLLIN}, {fd=88, events=POLLIN}], 13, 0) = 0 (Timeout)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="\31\0\v\0\367\212\240\2\0\0\0\0! \0\0\367\212\240\2\337\1\0\0006\r\0\0\0\0\0\0"..., iov_len=44}, {iov_base=NULL, iov_len=0}, {iov_base="", iov_len=0}], 3) = 44
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=27, events=POLLIN}, {fd=28, events=POLLIN}, {fd=29, events=POLLIN}, {fd=31, events=POLLIN}, {fd=32, events=POLLIN}, {fd=34, events=POLLIN}, {fd=35, events=POLLIN}, {fd=41, events=POLLIN}, {fd=46, events=POLLIN}, {fd=50, events=POLLIN}, {fd=88, events=POLLIN}], 13, 74) = 1 ([{fd=31, revents=POLLIN}])
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\34\0'\36\367\212\240\2\241\1\0\0<\t#\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 64
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="\24\0\6\0\367\212\240\2\241\1\0\0\6\0\0\0\0\0\0\0\377\377\377\377", iov_len=24}], 1) = 24
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="+\0\1\0", iov_len=4}, {iov_base=NULL, iov_len=0}, {iov_base="", iov_len=0}], 3) = 4
poll([{fd=31, events=POLLIN}], 1, -1) = 1 ([{fd=31, revents=POLLIN}])
recvmsg(31, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="T\1'\36\377\t\340\0\0\0\0\0007\r\0\0\0\0\0\0007\r\0\0?\t#\0\0\0\0\0"..., iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 176
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="\201\10\3\0\367\212\240\2\2\0\0\0", iov_len=12}, {iov_base=NULL, iov_len=0}, {iov_base="", iov_len=0}], 3) = 12
poll([{fd=31, events=POLLIN}], 1, -1) = 1 ([{fd=31, revents=POLLIN}])
recvmsg(31, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\1\3*\36\2\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 40
write(4, "\1\0\0\0\0\0\0\0", 8) = 8
poll([{fd=31, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=31, revents=POLLOUT}])
writev(31, [{iov_base="\217\3\4\0\0\n\340\0\0\0\0\0\0\0\0\0", iov_len=16}, {iov_base=NULL, iov_len=0}, {iov_base="", iov_len=0}], 3) = 16
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(5, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(31, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable)
extension data that was requested:
alan@server:~ -[] $ ls -al ~/.local/share/gnome-shell/extensions
total 12
drwxrwxr-x 3 alan alan 4096 May 25 2019 .
drwx------ 3 alan alan 4096 Jun 23 17:10 ..
drwxrwxr-x 3 alan alan 4096 May 25 2019 workspace-grid@mathematical.coffee.gmail.com
alan@server:~ -[] $ ls -al /usr/share/gnome-shell/extensions
total 20
drwxr-xr-x 5 root root 4096 Jun 17 18:38 .
drwxr-xr-x 7 root root 4096 Jun 17 18:39 ..
drwxr-xr-x 2 root root 4096 Jun 17 18:38 desktop-icons@csoriano
drwxr-xr-x 3 root root 4096 Jun 17 18:36 ubuntu-appindicators@ubuntu.com
drwxr-xr-x 3 root root 4096 Jun 17 18:36 ubuntu-dock@ubuntu.com
and complete top (snapshot)
Tasks: 405 total, 1 running, 404 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.5 us, 0.4 sy, 0.0 ni, 96.8 id, 0.1 wa, 0.0 hi, 0.2 si, 0.0 st
MiB Mem : 32015.4 total, 16744.1 free, 3038.5 used, 12232.8 buff/cache
MiB Swap: 32668.0 total, 32668.0 free, 0.0 used. 28377.6 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2709 alan 20 0 4596140 562652 135088 S 20.9 1.7 33:46.03 gnome-shell
9822 alan 20 0 4735696 201332 96160 S 3.3 0.6 8:56.20 chrome
9839 alan 20 0 4793876 197464 89324 S 3.3 0.6 6:19.33 chrome
2497 root 20 0 197440 68520 47796 S 2.7 0.2 1:43.00 Xorg
3213 alan 20 0 966064 58144 39524 S 2.3 0.2 1:24.41 gnome-terminal-
9732 alan 20 0 4794584 167996 87708 S 2.3 0.5 4:12.00 chrome
2973 alan 20 0 417144 31224 24820 S 2.0 0.1 3:49.59 indicator-multi
11800 alan 20 0 4688644 136292 87092 S 1.7 0.4 2:21.77 chrome
6196 alan 20 0 784460 261128 132512 S 1.3 0.8 3:20.76 chrome
1434 root -51 0 0 0 0 S 0.7 0.0 0:51.84 irq/50-nvidia
6236 alan 20 0 896856 255080 91376 S 0.7 0.8 5:10.00 chrome
1 root 20 0 168276 12092 8272 S 0.3 0.0 0:03.31 systemd
1100 systemd+ 20 0 24576 13672 9252 S 0.3 0.0 0:01.81 systemd-resolve
1436 root 20 0 0 0 0 S 0.3 0.0 0:08.46 nv_queue
2411 alan 20 0 9356 6668 4192 S 0.3 0.0 0:32.45 dbus-daemon
2972 alan 20 0 454696 33432 27780 S 0.3 0.1 0:44.40 indicator-netsp
3030 alan 20 0 7109676 247340 82260 S 0.3 0.8 0:24.37 dropbox
6238 alan 20 0 356452 97728 66520 S 0.3 0.3 0:37.41 chrome
11691 root 20 0 0 0 0 I 0.3 0.0 0:00.19 kworker/10:0-events
11832 alan 20 0 4626144 103308 73416 S 0.3 0.3 0:07.15 chrome
15438 alan 20 0 12396 4344 3396 R 0.3 0.0 0:00.06 top
2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_gp
4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_par_gp
6 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/0:0H-kblockd
9 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 mm_percpu_wq
10 root 20 0 0 0 0 S 0.0 0.0 0:00.26 ksoftirqd/0
11 root 20 0 0 0 0 I 0.0 0.0 0:07.61 rcu_sched
12 root rt 0 0 0 0 S 0.0 0.0 0:00.04 migration/0
13 root -51 0 0 0 0 S 0.0 0.0 0:00.00 idle_inject/0
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/0
15 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/1
16 root -51 0 0 0 0 S 0.0 0.0 0:00.00 idle_inject/1
17 root rt 0 0 0 0 S 0.0 0.0 0:00.25 migration/1
18 root 20 0 0 0 0 S 0.0 0.0 0:00.09 ksoftirqd/1
20 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/1:0H-kblockd
21 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/2
22 root -51 0 0 0 0 S 0.0 0.0 0:00.00 idle_inject/2
23 root rt 0 0 0 0 S 0.0 0.0 0:00.25 migration/2
Best Answer
Just in case anybody has a similar issue, I had CPU usage of 80% consistently from GNOME Shell and I switched the various extensions off for testing, on version 20.04.
It turned out I had the performance monitor in the top right hand side bar (system load monitor) - once that was quit, everything was back to normal. If anybody has any suggestions how to diagnose why I'm happy to test.