On 7/19/2018 1:39 AM, Greg KH wrote:
On Wed, Jul 18, 2018 at 10:09:44AM -0700, Andi Kleen wrote:
On Wed, Jul 18, 2018 at 11:29:50AM +0200, Greg KH wrote:
On Wed, Jul 18, 2018 at 08:41:28AM +0800, Jin, Yao wrote:
Hi,
The stable kernel 4.9.112 has supported Intel uncore feature in perf core.
While it also needs the perf tool supporting to let perf uncore feature
work.
Following backport patches enables basic perf uncore feature in 4.9.112.
For example, on skylake desktop,
Why would anyone care about this on a "desktop" for 4.9? No one should
be using 4.9.y on a desktop anymore, it's over 2 years old, why would
they expect any "new" hardware support to work for them? Why can't they
It's actually not new hardware support: Skylake is fairly old hardware
at this point.
So is 4.9. I don't understand your point. The hardware is obviously
newer than 4.9 was, otherwise the support for it would already be in
there, right?
just use 4.14.y or better yet. 4.17.y? Desktops should NOT be using a 2
year old kernel.
Heck, servers shouldn't either, but that's a totally different rant.
These chips are not only used in desktops but also in servers.
This was asked for with regards to desktops, so now I'm confused.
Exactly who/what is going to be needing/wanting/using these changes?
This patchset is not only regarding to desktop but also for servers.
Sorry, my example in patch description brings confusion.
The patchset supports the server like Skylake, and it also supports some
old servers, for example, Broadwell and Haswell.
4.9 kernel has uncore patches yet but at the perf tool side it doesn't
have associated uncore patches, so actually the perf uncore feature
doesn't work in 4.9.
We just want to enable the perf uncore feature in 4.9, it's especially
useful for server performance analysis.
Thanks
Jin Yao
However, for hardware that is newer than the base kernel version
release, I have no sympathy. Just use a newer kernel, right?
We have customers which are on old kernels with new hardware.
That's obviously not a wise thing to do for lots of good reasons. This
exact example being a huge one (i.e. you can't go back in time and add
support for hardware that was not out yet.)
The backports happen either way. This is just an attempt to do it in a
coordinated fashion.
There was no coordination here, just a list of git commit ids. Which is
great, and all that is really needed, but I'm confused as to who is
trying to coordinate with who?
What distro relies on a 4.9 kernel for brand new hardware that does not
already support a newer kernel release for such hardware?
None afaik, but there is a lot of Linux use beyond distros.
So no distro uses this, which makes me really wonder who would be the
user of these backports. And for how long? Why are these people not
moving to 4.14 already given that the published date for 4.9 end-of-life
is getting very close. Are you expecting to be rescued by Google again?
That can't be true as Android doesn't care about x86 servers :)
Please provide real solid information, including the answer to the other
question I asked in my response, which was not included here for some
reason.
thanks,
greg k-h
