Re: [BUG]smt sysfs dir missing on 4.4.148 and 4.14.63

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Aug 16, 2018 at 06:28:59PM +0200, Jinpu Wang wrote:
> On Thu, Aug 16, 2018 at 5:51 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Thu, Aug 16, 2018 at 05:43:23PM +0200, Jinpu Wang wrote:
> > > Hi Greg, hi Thomas,
> > >
> > > I noticed /sys/devices/system/cpu/smt dir is missing on 4.4.148 and
> > > 4.14.63, default setting.
> >
> > For 4.4, I would be amazed if anything was there, the backport was done
> > only to handle the local user issue, not the "full" protection.  So
> > please try 4.9 or 4.14.
> Thanks for quick reply. Right, just checked. the patch for create the
> sysfs entry is missing.

What patch is that?  What is the git commit id that we missed?

> > How about 4.17 and 4.18, do those trees work properly for you?
> I guess it's the same.
> >
> > > Tried stable/master branch 31130a16d459 ("Merge tag
> > > 'for-linus-4.19-rc1-tag' of
> > > git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip")
> > > It's the same there.
> >
> > Ah, so we are bug compatible, good :)
> I will try test stable master a bit more to gather the full log.
> >
> > > When boot with 'nosmt' kernel paramter kernel 4.14.63 panic during
> > > boot, 4.4.148 boot fine.
> > > The call trace seem irq related, is it known bug?
> >
> > You are not giving us much to go on here sorry.  We need full details,
> > and also please cc: lkml and the other developers who worked on this.
> > THomas is on vacation this week.
> Now, add more developers to cc, also lkml.
> 
> I have the config and boot dmesg attached for default setting.

I see no error in your boot log, what exactly are you worried about?

confused,

greg k-h