[MODERATED] Re: [PATCH v2 0/4] performance walnuts

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Mar 06, 2019 at 12:32:52PM -0600, speck for Mark Hatle wrote:
> On 3/6/19 12:08 PM, speck for Greg KH wrote:
> > On Wed, Mar 06, 2019 at 01:02:30PM +0000, speck for David Woodhouse wrote:
> >> On Wed, 2019-03-06 at 12:56 +0100, speck for Greg KH wrote:
> >>> On Wed, Mar 06, 2019 at 10:23:52AM +0100, speck for Thomas Gleixner wrote:
> >>>> On Tue, 5 Mar 2019, speck for Peter Zijlstra wrote:
> >>>>
> >>>>> Or whatever shiney new name they ought to get.
> >>>>>
> >>>>> Apparently the intent is to have these patches magically appears in source
> >>>>> repos on the 12th.
> >>>>
> >>>> I made them magically appear in the speck repo:
> >>>>
> >>>>   cvs.ou.linutronix.de:linux/speck/linux tsx-5.0
> >>>>
> >>>> and backports in the branches tsx-4.20, tsx-4.19, tsx-4.14. Git bundles
> >>>> are attached.
> >>>>
> >>>> I leave the dead kernel backports to the honorable members of the Kernel
> >>>> Necrophilia cult as usual.
> >>>
> >>> Many thanks for doing these backports.  I'll use them for the stable
> >>> updates next week.  As for kernels older than 4.14, I'll maybe try
> >>> 4.9 on my own...
> >>
> >> Let me know if you want me to take a look. I'm travelling next week so
> >> would have to try to squeeze it in this week.
> > 
> > Do you all really care about 4.9.y anymore?  I thought you all had moved
> > off of it to 4.14.y already.  I'll look at it tomorrow and see how bad
> > it looks...
> 
> As painful as it is, we (and others) have customers on ancient kernels with no
> way to upgrade for a variety of technical, regulatory and business reasons.  But
> we don't expect you to start digging up old kernel and applying patches back.

And all of those kernels are almost guaranteed to be vulnerable to _WAY_
more than just this simple issue, unless they happen to also be taking
the stable/LTS kernel updates (or they are running a well-supported
"enterprise" kernel).

So while it is fun for people to want to claim they "need" these
patches, what they really "need" is to fix those
technical/regulatory/business "reasons" to not ensure that they are
guaranteeing they will always have broken systems.

Yeah, I know I'm preaching to the chior here, but note, I have gotten
the US cellular carriers to now rubber-stamp LTS kernel upgrades for
Android phones.  It wasn't really that hard in the end, most of them
said, "we were waiting for you to ask, of course it is ok!", all it took
was pushing through the layers of management who thought they knew what
they were doing...

Sorry for the rant, but this has been a pet-peeve of mine for a long
time and something I have worked hard for the past 5 years to fix.
Please don't perpetuate the problems if you can help it.

greg k-h