[BUG] btop crashes when number of CPU cores enabled < number of CPU cores total

[BSGalvan]

Describe the bug

btop crashes with an error when only some of the available cores on a CPU are configured to run.
The error message is this: ERROR: Exception in Shared::init() -> collect() : stoi

To Reproduce

The initial error occurred on a work desktop which I do not have access to as of writing this.
On it however, 16 out of 32 CPU cores were enabled.

CPU cores can be manually disabled using chcpu(8), so this is what I did to reproduce the error on my Ryzen 7 4750U laptop:

1. sudo chcpu -d 4-15 (kind of overkill, but on another laptop with an i5-7200U, knocking out 1 or 2 did suffice)
2. run btop, which throws this error: ERROR: Exception in Shared::init() -> collect() : stoi

Expected behavior

btop should show at least the usual UI, but with lesser CPUs in the 'CPU' box (which indicates that some of them are disabled).

This is what it shows now:

Whereas this is what I expect it to show:

Note: I was able to get the above by reverting the change in 96b770c. However, I do not know if that is a sensible bug fix, hence an issue instead of a PR!

Screenshots

Info (please complete the following information):

• btop++ version: 1.2.9
• Binary: compiled from source, at commit 2b02a66
• (If compiled) Compiler and version: gcc version 11.3.0 (Gentoo Hardened 11.3.0 p4)
• Architecture: x86_64
• Platform: Linux
• (Linux) Kernel: 5.15.69-gentoo
• (OSX/FreeBSD) Os release version: N/A
• Terminal used: st
• Font used: FiraCode NerdFont

Additional context

Contents of ~/.config/btop/btop.log:

2022/10/05 (12:49:02) | ===> btop++ v.1.2.9
2022/10/05 (12:49:02) | DEBUG: Starting in DEBUG mode!
2022/10/05 (12:49:02) | INFO: Logger set to DEBUG
2022/10/05 (12:49:02) | DEBUG: Using locale en_US.utf8
2022/10/05 (12:49:02) | INFO: Running on /dev/pts/3
2022/10/05 (12:49:02) | DEBUG: get_cpuHz() : stoi
2022/10/05 (12:49:02) | ERROR: Exception in Shared::init() -> collect() : stoi
2022/10/05 (12:49:02) | INFO: Quitting! Runtime: 00:00:00

GDB Backtrace

GNU gdb (Gentoo 11.2 vanilla) 11.2
--- omitted for brevity ---
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from btop...
(No debugging symbols found in btop)
(gdb) r
Starting program: /usr/bin/btop
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
ERROR: Exception in Shared::init() -> collect() : stoi
[Inferior 1 (process 3197) exited with code 01]
(gdb) thread apply all bt
(gdb)

[aristocratos]

@BSGalvan
Can you post the output of /proc/stat when you have some cores disabled.

[BSGalvan]

Here you go, output of cat /proc/stat after chcpu -d 4-15:

cpu  585677 3980 141041 6709601 3496 0 1849 0 0 0
cpu0 106694 522 23916 862478 1109 0 1531 0 0 0
cpu1 74817 217 20002 3498 8 0 67 0 0 0
cpu2 79505 540 22266 3354 6 0 96 0 0 0
cpu3 72573 557 19701 3442 8 0 13 0 0 0
intr 30075083 114 323 0 0 0 0 0 0 12680 9339 0 0 982 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 198 6568 0 0 0 0 37 22 0 0 0 0 0 0 0 0 0 168 101 56 75 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 126054 53866 1730 2783 2307 919 2645 1565 1100 2455 1332 2974 29062 2042 4783 17 1662806 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
ctxt 47713632
btime 1664947501
processes 80959
procs_running 1
procs_blocked 0
softirq 13138886 86712 1261465 163 237461 115 0 38543 5111595 162 6402670

[aristocratos]

@BSGalvan
Was a counting issue, the last core was missed if not enabled. Fixed in latest commit.
Binaries: https://github.com/aristocratos/btop/actions/runs/3188452086

[BSGalvan]

Awesome! Thanks for the quick fix 😄
Closing.