Re: [PATCH v6 18/19] x86: Add support for generic vDSO

From: Sasha Levin <sashal@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Michael Kelley <mikelley@microsoft.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
	"linux-kselftest@vger.kernel.org"
	<linux-kselftest@vger.kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>, Arnd Bergmann <arnd@arndb.de>,
	Russell King <linux@armlinux.org.uk>,
	Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paul.burton@mips.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Mark Salyzyn <salyzyn@android.com>,
	Peter Collingbourne <pcc@google.com>,
	Shuah Khan <shuah@kernel.org>,
	Dmitry Safonov <0x7f454c46@gmail.com>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Huw Davies <huw@codeweavers.com>,
	linux-hyperv@vger.kernel.org,
	Greg KH <gregkh@linuxfoundation.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: [PATCH v6 18/19] x86: Add support for generic vDSO
Date: Sun, 23 Jun 2019 15:09:29 -0400	[thread overview]
Message-ID: <20190623190929.GL2226@sasha-vm> (raw)
In-Reply-To: <alpine.DEB.2.21.1906221542270.5503@nanos.tec.linutronix.de>

On Sat, Jun 22, 2019 at 04:46:28PM +0200, Thomas Gleixner wrote:
>On Fri, 14 Jun 2019, Sasha Levin wrote:
>> On Fri, Jun 14, 2019 at 01:15:23PM +0200, Thomas Gleixner wrote:
>> > On Thu, 30 May 2019, Michael Kelley wrote:
>> > > Vincenzo -- these changes for Hyper-V are a subset of a larger patch set
>> > > I have that moves all of the Hyper-V clock/timer code into a separate
>> > > clocksource driver in drivers/clocksource, with an include file in
>> > > includes/clocksource.  That new include file should be able to work
>> > > instead of your new mshyperv-tsc.h.  It also has the benefit of being
>> > > ISA neutral, so it will work with my in-progress patch set to support
>> > > Linux on Hyper-V on ARM64.  See https://lkml.org/lkml/2019/5/27/231
>> > > for the new clocksource driver patch set.
>> >
>> > Grrr. That's queued in hyperv-next for whatever reasons.
>>
>> I queue up our future pull requests there to give them some soaking in
>> -next.
>
>What? You queue completely unreviewed stuff which touches two other
>subsystems to let it soak in next?

It was out on LKML for 2+ weeks before I've pulled it in. As it mostly
touches hyperv bits I felt comfortable to give it time in -next (but not
actually to try and merge it until it gets a few acks).

>> > Sasha, can you please provide me the branch to pull from so I can have a
>> > common base for all the various changes floating around?
>>
>> I'll send you a unified pull request for these changes.
>
>Which has not materialized yet.

Appologies about this. I ended up with way more travel than I would have
liked (writing this from an airport). I've reset our hyperv-next branch
to remove these 3 commits until we figure this out.

>TBH, I'm pretty grumpy about those clocksource changes. Here is the
>diffstat:
>
> MAINTAINERS                          |    2
> arch/x86/entry/vdso/vclock_gettime.c |    1
> arch/x86/entry/vdso/vma.c            |    2
> arch/x86/hyperv/hv_init.c            |   91 ---------
> arch/x86/include/asm/hyperv-tlfs.h   |    6
> arch/x86/include/asm/mshyperv.h      |   81 +-------
> arch/x86/kernel/cpu/mshyperv.c       |    2
> arch/x86/kvm/x86.c                   |    1
> drivers/clocksource/Makefile         |    1
> drivers/clocksource/hyperv_timer.c   |  322 +++++++++++++++++++++++++++++++++++
> drivers/hv/Kconfig                   |    3
> drivers/hv/hv.c                      |  156 ----------------
> drivers/hv/hv_util.c                 |    1
> drivers/hv/hyperv_vmbus.h            |    3
> drivers/hv/vmbus_drv.c               |   42 ++--
> include/clocksource/hyperv_timer.h   |  105 +++++++++++
>
>While the world and some more people have been CC'ed on those patches,
>neither the clocksource nor the x86 maintainer have been.
>
>When I gave Vincenzo the advise to base his code on that hyper-v branch, I
>expected that I find the related patches in my mail backlog. No, they have
>not been there because I was not on CC.
>
>Folks, please stop chosing Cc lists as you like. We have well established
>rules for that. And please stop queueing random unreviewed patches in
>next. Next is not a playground for not ready and unreviewed stuff. No, the
>hyper-v inbreed Reviewed-by is not sufficient for anything x86 and
>clocksource related.

I'm sorry for this, you were supposed to be Cc'ed on these patches and I
see that you were not.

>After chasing and looking at those patches, which have horrible subject
>lines and changelogs btw, I was not able to judge quickly whether that
>stuff is self contained or not. So no, I fixed up the fallout and rebased
>Vincenzos VDSO stuff on mainline w/o those hyperv changes simply because if
>they are not self contained they will break bisection badly.
>
>I'm going to push out the VDSO series later today. That will nicely break
>in combination with the hyper-next branch. Stephen, please drop that and do
>not try to handle the fallout. That stuff needs to go through the proper
>channels or at least be acked/reviewed by the relevant maintainers. So the
>hyper-v folks can rebase themself and post it proper.

Okay, thank you. We'll rebase and resend.

--
Thanks,
Sasha