To: alpine-user <alpine-user@lists.alpinelinux.org>
From: Riccardo Mottola <riccardo.mottola@libero.it>
Subject: performance drop with alpine linux upgrade
Message-ID: <196e1b55-ade9-8a4b-889b-006fef7f63c1@libero.it>
Date: Mon, 12 Sep 2022 10:47:05 +0200
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Hello,

I upgraded Alpine Linux to 3.16 on my old Celeron-based Laptop.

now, the same task of compiling the Arctic Fox browser takes instead of
about 4 hours, almost 10 days!! I extra left it running until I get the
same compile error as before.
It is a bit extreme performance drop!
I noticed that while compiling, the laptop fan does not ran constantly
at high speed, but it remains quited for a period, then spins up, then
quiet again, even if CPU is 100%.

I can think of two causes, from my past experience with other systems:
- disabled caches
- CPU not runnig at full speed

In the BIOS I checked and CPU and L2 caches are enabled (small in this
crippled CPU anyway).
Could some APM/ACPI lower the cpu speed until I rise it withsome governor?

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Mobile Intel(R) Celeron(R) CPU 2.20GHz
stepping        : 9
microcode       : 0x10
cpu MHz         : 2194.366
cache size      : 256 KB
physical id     : 0
siblings        : 1
core id         : 0
cpu cores       : 1
apicid          : 0
initial apicid  : 0
fdiv_bug        : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts
cpuid cid xtpr
bugs            : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass
l1tf mds swapgs itlb_multihit
bogomips        : 4390.59
clflush size    : 64
cache_alignment : 128
address sizes   : 36 bits physical, 32 bits virtual
power management:

Could some of the bug mitigation have such a strong impact? How can I
disable them in alpine? I don't think they would be a safety concern for
the kind of usage I have.

Riccardo