Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 6 Jul 2018 12:00:08 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     KY Srinivasan <kys@microsoft.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "devel@linuxdriverproject.org" <devel@linuxdriverproject.org>,
        "olaf@aepfle.de" <olaf@aepfle.de>,
        "apw@canonical.com" <apw@canonical.com>,
        "jasowang@redhat.com" <jasowang@redhat.com>,
        "hpa@zytor.com" <hpa@zytor.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>,
        "vkuznets@redhat.com" <vkuznets@redhat.com>
Subject: Re: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI
 enlightenment.
Message-ID: <20180706100008.GA3483@gmail.com>
References: <20180703230155.15160-1-kys@linuxonhyperv.com>
 <20180704161039.GA23658@gmail.com>
 <MW2PR2101MB111396005B0F5572C92B4CD7A0400@MW2PR2101MB1113.namprd21.prod.outlook.com>
 <20180705153820.GA26768@gmail.com>
 <MW2PR2101MB1113ABC82EC62E2C8DBA2400A0400@MW2PR2101MB1113.namprd21.prod.outlook.com>
 <20180705222302.GB5410@gmail.com>
 <alpine.DEB.2.21.1807060043290.1771@nanos.tec.linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <alpine.DEB.2.21.1807060043290.1771@nanos.tec.linutronix.de>
User-Agent: Mutt/1.9.4 (2018-02-28)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


* Thomas Gleixner <tglx@linutronix.de> wrote:

> On Fri, 6 Jul 2018, Ingo Molnar wrote:
> > * KY Srinivasan <kys@microsoft.com> wrote:
> > > I am confused. The label ipi_mask_done was introduced in this patch
> > > (the patch under question fixes a circular dependency in this patch):
> > > 
> > > commit 68bb7bfb7985df2bd15c2dc975cb68b7a901488a
> > > Author: K. Y. Srinivasan <kys@microsoft.com>
> > > Date:   Wed May 16 14:53:31 2018 -0700
> > > 
> > >     X86/Hyper-V: Enable IPI enlightenments
> > > 
> > >     Hyper-V supports hypercalls to implement IPI; use them.
> > > 
> > >     Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > >     Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > >     Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> > > 
> > > This patch was committed by Thomas some weeks ago and is in linux-next.
> > > This patch is also in 4.18-rc3.
> > 
> > And then that name was changed to a different label in:
> > 
> >   4bd06060762b: x86/hyper-v: Use cheaper HVCALL_SEND_IPI hypercall when possible
> > 
> > So maybe you were testing on an older kernel. Could you try the latest -tip?
> 
> The problem is that the wreckage is in Linus tree and needs to be fixed
> there, i.e. via x86/urgent.

Indeed, I missed that!

> Now we have the new bits queued in x86/hyperv already which collide. So we
> need to merge x86/urgent into x86/hyperv after applying the fix and mop up
> the merge wreckage in x86/hyperv.
> 
> I'll have a look tomorrow morning unless you beat me to it.

Ok!

Thanks,

	Ingo