Re: [Xenomai] [PULL] ipipe: fixes for 3.14

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2015-02-17 15:49, Jan Kiszka wrote:
> Retested and, although I could have sworn that !CONFIG_IPIPE doesn't
> cause this effect, it does on 3.14.28. And checking CPU features again,
> there is both "hle" and "rtm" - in contrast to a newer 3.18 kernel where
> those are gone (same distro, same hardware).
> 
> So this is not an I-pipe issue, it's something related to the kernel or
> its configuration. Need to study again where the microcode comes from. I
> thought it was pulled from /lib/firmware/somewhere, thus would be shared
> between all kernels on the same rootfs.

Just to close the topic: We had early microcode loading disabled in the
kernel, likely due to some historic reasons (there was a crash once).
That caused systemd to load libpthread before the microcode fix that
disables RTM was loaded. Once the microcode came in, the RTM
instructions suddenly start to cause #UD. Nice. Not sure yet if this
explains the issues in the customer application - we will see later.

Jan

-- 
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux