Re: [PATCH 00/11] VMBus channel interrupt reassignment

From: Andrea Parri <parri.andrea@gmail.com>
To: Wei Liu <wei.liu@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	"K . Y . Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	linux-hyperv@vger.kernel.org,
	Michael Kelley <mikelley@microsoft.com>,
	Dexuan Cui <decui@microsoft.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Andrew Murray <amurray@thegoodpenguin.co.uk>,
	Bjorn Helgaas <bhelgaas@google.com>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: [PATCH 00/11] VMBus channel interrupt reassignment
Date: Mon, 13 Apr 2020 19:07:39 +0200	[thread overview]
Message-ID: <20200413170739.GA28863@andrea> (raw)
In-Reply-To: <20200413154836.rfvkbcg654pc5t5n@debian>

On Mon, Apr 13, 2020 at 04:48:36PM +0100, Wei Liu wrote:
> On Mon, Apr 06, 2020 at 02:15:03AM +0200, Andrea Parri (Microsoft) wrote:
> > Hi all,
> > 
> > This is a follow-up on the RFC submission [1].  The series introduces
> > changes in the VMBus drivers to reassign the CPU that a VMbus channel
> > will interrupt.  This feature can be used for load balancing or other
> > purposes (e.g. CPU offlining).  The submission integrates feedback in
> > the RFC to amend the handling of the 'array of channels' (patch #3).
> > 
> > Thanks,
> >   Andrea
> > 
> > [1] https://lkml.kernel.org/r/20200325225505.23998-1-parri.andrea@gmail.com
> > 
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Cc: Andrew Murray <amurray@thegoodpenguin.co.uk>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> > Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> > 
> > Andrea Parri (Microsoft) (11):
> >   Drivers: hv: vmbus: Always handle the VMBus messages on CPU0
> >   Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific
> >     CPU
> >   Drivers: hv: vmbus: Replace the per-CPU channel lists with a global
> >     array of channels
> >   hv_netvsc: Disable NAPI before closing the VMBus channel
> >   hv_utils: Always execute the fcopy and vss callbacks in a tasklet
> >   Drivers: hv: vmbus: Use a spin lock for synchronizing channel
> >     scheduling vs. channel removal
> >   PCI: hv: Prepare hv_compose_msi_msg() for the
> >     VMBus-channel-interrupt-to-vCPU reassignment functionality
> >   Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity
> >     logic
> >   Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug
> >   Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message
> >     type
> >   scsi: storvsc: Re-init stor_chns when a channel interrupt is
> >     re-assigned
> > 
> 
> Applied to hyperv-next. Thanks.
> 
> This hunk in patch 10 doesn't apply cleanly because it conflicts with
> Vitaly's patch.
> 
> diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
> index 3785beead503d..1058c814ab06e 100644
> --- a/drivers/hv/channel_mgmt.c
> +++ b/drivers/hv/channel_mgmt.c
> @@ -1377,7 +1377,7 @@ channel_message_table[CHANNELMSG_COUNT] = {
>         { CHANNELMSG_19,                        0, NULL },
>         { CHANNELMSG_20,                        0, NULL },
>         { CHANNELMSG_TL_CONNECT_REQUEST,        0, NULL },
> -       { CHANNELMSG_22,                        0, NULL },
> +       { CHANNELMSG_MODIFYCHANNEL,             0, NULL },
>         { CHANNELMSG_TL_CONNECT_RESULT,         0, NULL },
>  };
> 
> I have fixed it up. New hunk looks like:
> 
> diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
> index a6b21838e2de..9c62eb5e4135 100644
> --- a/drivers/hv/channel_mgmt.c
> +++ b/drivers/hv/channel_mgmt.c
> @@ -1380,7 +1380,7 @@ channel_message_table[CHANNELMSG_COUNT] = {
>         { CHANNELMSG_19,                        0, NULL, 0},
>         { CHANNELMSG_20,                        0, NULL, 0},
>         { CHANNELMSG_TL_CONNECT_REQUEST,        0, NULL, 0},
> -       { CHANNELMSG_22,                        0, NULL, 0},
> +       { CHANNELMSG_MODIFYCHANNEL,             0, NULL, 0},
>         { CHANNELMSG_TL_CONNECT_RESULT,         0, NULL, 0},
>  };

The fix looks good to me.  Thank you Wei!

Thanks,
  Andrea