cosmic-greeter uses 100% cpu when the display is asleep

[estokes]

trafficstars

as of cosmic-greeter 0.1.0~1742842290~24.04~f826b8c I've noticed the fan on my laptop (lemur pro) going crazy when the display is asleep. If I switch to another VT and run htop I can see that cosmic-greeter is constantly using 100% of a single core.

I'm fairly sure I've reproduced this in an empty session, however I normally have brave, emacs, terminals, signal and discord running when my screen locks, and with that setup it happens every time.

I did have my display set to 48hz refresh to save a tiny bit of power and I've just undone that to see if it stops triggering this (it's a stretch, but who knows).

[estokes]

I managed to catch it and get a perf report, you can get some idea what the process is doing, I'll spare you the full 128k, but here are the relevant bits,

# Overhead  Command          Shared Object                Symbol
# ........  ...............  ...........................  .........................................
#
     3.95%  cosmic-greeter   [kernel.kallsyms]            [k] fput
     3.63%  cosmic-greeter   [kernel.kallsyms]            [k] _copy_to_user
     3.50%  cosmic-greeter   [kernel.kallsyms]            [k] entry_SYSRETQ_unsafe_stack
     3.29%  cosmic-greeter   [kernel.kallsyms]            [k] _copy_from_user
     3.19%  cosmic-greeter   libc.so.6                    [.] pthread_mutex_lock
     2.67%  cosmic-greeter   [vdso]                       [.] 0x0000000000000c46
     2.55%  cosmic-greeter   [kernel.kallsyms]            [k] do_epoll_ctl
     2.47%  cosmic-greeter   [kernel.kallsyms]            [k] entry_SYSCALL_64
     1.67%  cosmic-greeter   cosmic-greeter               [.] 0x000000000021ddc1
     1.57%  cosmic-greeter   [kernel.kallsyms]            [k] call_function_single_prep_ipi
     1.41%  cosmic-greeter   [kernel.kallsyms]            [k] x64_sys_call
     1.39%  cosmic-greeter   cosmic-greeter               [.] 0x0000000000d378d3
     1.38%  cosmic-greeter   cosmic-greeter               [.] 0x000000000022386f
     1.35%  cosmic-greeter   [kernel.kallsyms]            [k] fdget
     1.34%  cosmic-greeter   [kernel.kallsyms]            [k] vfs_read
     1.31%  cosmic-greeter   [kernel.kallsyms]            [k] _raw_spin_lock_irq
     1.26%  cosmic-greeter   [kernel.kallsyms]            [k] __raw_spin_lock_irqsave
     1.17%  cosmic-greeter   [kernel.kallsyms]            [k] put_itimerspec64
     1.05%  cosmic-greeter   cosmic-greeter               [.] 0x0000000000d3542c
     1.02%  cosmic-greeter   [kernel.kallsyms]            [k] entry_SYSCALL_64_after_hwframe
     0.96%  cosmic-greeter   libc.so.6                    [.] pthread_mutex_unlock
     0.86%  cosmic-greeter   [kernel.kallsyms]            [k] apparmor_file_permission
     0.81%  cosmic-greeter   libc.so.6                    [.] 0x0000000000188bd3
     0.79%  cosmic-greeter   cosmic-greeter               [.] 0x0000000000cfc567
     0.71%  cosmic-greeter   [kernel.kallsyms]            [k] security_file_permission
     0.70%  cosmic-greeter   [kernel.kallsyms]            [k] entry_SYSCALL_64_safe_stack
     0.69%  cosmic-greeter   [kernel.kallsyms]            [k] syscall_return_via_sysret
     0.69%  cosmic-greeter   [kernel.kallsyms]            [k] ep_item_poll.isra.0
     0.69%  cosmic-greeter   cosmic-greeter               [.] 0x000000000036c741
     0.68%  cosmic-greeter   [kernel.kallsyms]            [k] get_itimerspec64
     0.68%  cosmic-greeter   cosmic-greeter               [.] 0x0000000000cfc4ec
     0.66%  cosmic-greeter   cosmic-greeter               [.] 0x0000000000717630
     0.65%  cosmic-greeter   libc.so.6                    [.] 0x0000000000188a0d
     0.64%  cosmic-greeter   [kernel.kallsyms]            [k] mutex_lock

[estokes]

I also confirm that 48 vs 60 hz doesn't matter. And, it doesn't stop doing it when the display wakes up, it keeps going until I unlock the display.

[zero-hugo]

I’ve encountered the same issue: after the screen turns off, the fan spins wildly. I suspect it’s caused by abnormal CPU usage. When I wake the screen, the fan gradually slows down. However, I’m unsure if this is directly related to cosmic-greeter.

[runlevel5]

I too experience the same issue on my Thinkpad X1 Gen 9, the fan spin loudly and once the screen is fully awake, the spinning gradually slow down.

[marchaesen]

Same thing with me. When it is in this codition, and I run the top command in a virtual terminal, I see the cosmic-greeter process taking 100 % CPU of one core. When I log back in, the CPU of the cosmis-greeter process goes back to 0.

[jacobgkau]

I'm seeing this on the serw13.