Laggy gnome after 100% battery and disconnect power cable

Ask Fedora
1

Not sure how to reproduce this issue, but sometimes, just sometimes, when i get 100% battery charge and remove power cable, gnome becomes laggy. clicks, zoom, animations, everything stutters.

my system is the following

CPU:
Info: 8-core model: AMD Ryzen 9 7940HS w/ Radeon 780M Graphics bits: 64
type: MT MCP cache: L2: 8 MiB
Speed (MHz): avg: 1101 min/max: 403/5263 cores: 1: 1101 2: 1101 3: 1101
4: 1101 5: 1101 6: 1101 7: 1101 8: 1101 9: 1101 10: 1101 11: 1101 12: 1101
13: 1101 14: 1101 15: 1101 16: 1101
Flags: 3dnowprefetch abm adx aes amd_lbr_pmc_freeze amd_lbr_v2 aperfmperf
apic arat avx avx2 avx512_bf16 avx512_bitalg avx512_vbmi2 avx512_vnni
avx512_vpopcntdq avx512bw avx512cd avx512dq avx512f avx512ifma avx512vbmi
avx512vl bmi1 bmi2 bpext cat_l3 cdp_l3 clflush clflushopt clwb clzero
cmov cmp_legacy constant_tsc cpb cppc cpuid cpuid_fault cqm cqm_llc
cqm_mbm_local cqm_mbm_total cqm_occup_llc cr8_legacy cx16 cx8 de
decodeassists erms extapic extd_apicid f16c flush_l1d flushbyasid fma fpu
fsgsbase fxsr fxsr_opt gfni ht hw_pstate ibpb ibrs ibrs_enhanced ibs
invpcid irperf lahf_lm lbrv lm mba mca mce misalignsse mmx mmxext monitor
movbe msr mtrr mwaitx nonstop_tsc nopl npt nrip_save nx ospke osvw
overflow_recov pae pat pausefilter pclmulqdq pdpe1gb perfctr_core
perfctr_llc perfctr_nb perfmon_v2 pfthreshold pge pku pni popcnt pse
pse36 rapl rdpid rdpru rdrand rdseed rdt_a rdtscp rep_good sep sha_ni
skinit smap smca smep ssbd sse sse2 sse4_1 sse4_2 sse4a ssse3 stibp
succor svm svm_lock syscall tce topoext tsc tsc_scale umip user_shstk
v_spec_ctrl vaes vgif vmcb_clean vme vmmcall vnmi vpclmulqdq wbnoinvd wdt
x2apic x2avic xgetbv1 xsave xsavec xsaveerptr xsaveopt xsaves xtopology

thanks in advance for any guidance

2

Many, if not most, laptops reduce cpu clock speed to minimum when on battery and run at near max speed when on power.

I suspect this may be the difference you are seeing in performance.
Your post shows the cpu clocked at just a little over minimum.

3

Hello Jeff! Thanks a lot for the reply.

I thought the same at first, but the cpu autoscaling and power profiles behave differently from this specific scenario.

On very low power or setting manually the power save mode, gnome keeps working smoothly.

The randomness of the event is what bugs me more.

I hope to discover how to repoduce it with 100% accuracy, but for now that’s all the info i got.

4

Are you using auto-cpufreq?

You might get useful details by running journalctl —follow in a terminal before removing the power cable. Power management on x86_64 laptops is struggling to match battery runtimes of Apple Silicon, so reducing power for “idle” devices like keyboard lights as well as CPU speeds, so UEFI/BIOS updates may affect power profiles.