Re: UFS bad inode, mangled entry on Alder Lake-N(100)

On 2025-01-28 06:23, Milan Obuch wrote:
> On Mon, 27 Jan 2025 19:28:28 +0100
> Yamagi <lists@yamagi.org> wrote:
> 
>> Hi,
>>
>> sounds like the Alder Lakes PCID bug in N100 flavor. On the small
>> cores the INVLPG instruction is broken, failing to flush all
>> (global?) TLP entries leading to cache corruption. FreeBSD has a work
>> around for
>> that: https://cgit.freebsd.org/src/commit/?id=cde70e312c3fde5b37a29be1dacb7fde9a45b94a
>>
>> However that work around never fully solved the problem on the N100
>> series. My own N100 board was never stable with PCID enabled and
>> there are several other reports of the same problems. For example
>> https://lists.freebsd.org/archives/freebsd-current/2023-August/004116.html
>>
>> Since Linux went with disabling PCID all together on all Alder Lake
>> and Raptor LAKE CPUs, I did the same by setting
>> vm.pmap.pcid_enabled=0 in loader.conf. Since I did that the system is
>> running fine.
>>
>> The Linux commit  disabling PCID is here:
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ae8373a5add4ea39f032563cf12a02946d1e3546
>>
>> A microcode update might also help. I didn't test the updates
>> released by Intel since early last year so I don't know for sure.
>>
> 
> It looks like the right thing, in my case adding vm.pmap.pcid_enabled=0
> to /boot/loader.conf helps. I consider this easier than installing port
> for microcode update...
> 
> That being said, could someone add some more pro/cons for those two
> approaches?
> 
> Additionally, I am using M.2 SATA drive at the moment. While NVMe drive
> worked to some extent, if fsck was necessary for some reason, it was
> unpleasant - some 'waiting for nvme reset' event occured, this led to
> nvme drive detach, and the only way to fix it was unscrew the drive,
> put it in USB-NVMe converter, do fsck via USB drive, then mount it back
> into box... not acceptable.

I chose microcode but that was hard to do because I only have one nvme 
slot and the installer panicked trying to install the package at the 
final part of the install. I had to install onto an SD and then use 
another FreeBSD install to do a pkg chroot install onto that temporary 
media and then use that to boot with the firmware update and chroot 
install the firmware and edit loader.conf on the nvme.

The microcode update fixed it for me. I inferred from reading that 
enable PCID might have a performance advantage.

Ian