Re: [regression] oops on heavy compilations ("kernel BUG at mm/zswap.c:1005!" and "Oops: invalid opcode: 0000")

[Piotr Oniszczuk]

> Wiadomość napisana przez Matthew Wilcox <willy@xxxxxxxxxxxxx> w dniu 23.08.2024, o godz. 15:13:
> 
> I wouldn't be surprised if this were dodgy ram.


Well - that was my initial hypothesis.

in fact i had few of them. Ranked (and ordered) like this:
1. downstream kernel patches
2. hw (ram) issue
3. kernel bug

So full history was:
-build myself archlinux 6.10.2 kernel; upgrade builder OS (only kernel; nothing else)
-run normal devel process and (to my surprise) discover interrupted CI/CD builds by kernel oops
-downgrade to 6.8.2 and done 4 full builds (full takes 8..9h of constant 12c/24/t compile). all good.  
-prepare vanilla 6.10.6 (to exclude potential downstream (ArchLinux) root causes)
-run normal devel process and still discover oops
-make sure hw is ok by week of test with 6.8.2 (recompiling for 3 architectures on 4 OS (3 in kvm). This was almost 5 full days of 12c/24 compiling. All good
-because last steep was all good - decide to go to you :-)

sure - this is possible that 6.8.2 had luck with my ram and 6.10.6 had no luck….but i personally don’t believe this is a case….     

btw: we can go with elimination strategy.
So what i need to change/disable to be closer to finding root cause?
swap?
now it is swapfile on system nvme