Re: [patch 00/37] cpu/hotplug, x86: Reworked parallel CPU bringup

From: Paul Menzel
Date: Mon Apr 17 2023 - 08:02:16 EST


[Correct David’s address]

Am 17.04.23 um 13:19 schrieb Paul Menzel:
Dear Thomas,


Am 15.04.23 um 01:44 schrieb Thomas Gleixner:

This is a complete rework of the parallel bringup patch series (V17)

https://lore.kernel.org/lkml/20230328195758.1049469-1-usama.arif@xxxxxxxxxxxxx

to address the issues which were discovered in review:

[…]

Thank you very much for your rework.

I tested this on the ASUS F2A85-M PRO, and get a delay of ten seconds.

```
[…]
[    0.258193] smpboot: CPU0: AMD A6-6400K APU with Radeon(tm) HD Graphics (family: 0x15, model: 0x13, stepping: 0x1)
[…]
[    0.259329] smp: Bringing up secondary CPUs ...
[    0.259527] x86: Booting SMP configuration:
[    0.259528] .... node  #0, CPUs:      #1
[    0.261007] After schedule_preempt_disabled
[   10.260990] CPU1 failed to report alive state
[   10.261070] smp: Brought up 1 node, 1 CPU
[   10.261073] smpboot: Max logical packages: 2
[   10.261074] smpboot: Total of 1 processors activated (7800.54 BogoMIPS)
[   10.261601] devtmpfs: initialized
[   10.261697] x86/mm: Memory block size: 128MB
```

This delay has been there with v6.3-rc6-46-gde4664485abbc and some custom (printk) patches on top and merging dwmw2/parallel-6.2-rc3-v16 into it. I only tested this. I think dwmw2/parallel-6.2-v17 failed to build for me, when trying to merge it into Linus’ master version at that time. I didn’t come around to report it, and you posted your rework, so I am replying here.

I am going to try your branch directly in the next days, but just wanted to report back already.


Kind regards,

Paul