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From: Dexuan Cui <decui@microsoft.com>
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	KY Srinivasan <kys@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>
Cc: "olaf@aepfle.de" <olaf@aepfle.de>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	"driverdev-devel@linuxdriverproject.org"
	<driverdev-devel@linuxdriverproject.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>,
	"marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>,
	"apw@canonical.com" <apw@canonical.com>,
	"vkuznets@redhat.com" <vkuznets@redhat.com>,
	"jasowang@redhat.com" <jasowang@redhat.com>
Subject: [PATCH] Drivers: hv: vmbus: do not mark HV_PCIE as perf_device
Date: Sat, 3 Mar 2018 00:22:19 +0000	[thread overview]
Message-ID: <20180303002155.20689-2-decui@microsoft.com> (raw)
In-Reply-To: <20180303002155.20689-1-decui@microsoft.com>

The pci-hyperv driver's channel callback hv_pci_onchannelcallback() is not
really a hot path, so we don't need to mark it as a perf_device, meaning
with this patch all HV_PCIE channels' target_cpu will be CPU0.

This patch can help to avoid a potential ABBA deadlock in the busy loop
of Hyper-V PCI driver's hv_compose_msi_msg().

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: stable@vger.kernel.org
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/channel_mgmt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index c21020b69114..55ee5e87073a 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -71,7 +71,7 @@ static const struct vmbus_device vmbus_devs[] = {
 	/* PCIE */
 	{ .dev_type = HV_PCIE,
 	  HV_PCIE_GUID,
-	  .perf_device = true,
+	  .perf_device = false,
 	},
 
 	/* Synthetic Frame Buffer */
-- 
2.7.4
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WARNING: multiple messages have this Message-ID (diff)
From: Dexuan Cui <decui@microsoft.com>
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	KY Srinivasan <kys@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"driverdev-devel@linuxdriverproject.org"
	<driverdev-devel@linuxdriverproject.org>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	"olaf@aepfle.de" <olaf@aepfle.de>,
	"apw@canonical.com" <apw@canonical.com>,
	"jasowang@redhat.com" <jasowang@redhat.com>,
	"vkuznets@redhat.com" <vkuznets@redhat.com>,
	"marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>,
	Dexuan Cui <decui@microsoft.com>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: [PATCH] Drivers: hv: vmbus: do not mark HV_PCIE as perf_device
Date: Sat, 3 Mar 2018 00:22:19 +0000	[thread overview]
Message-ID: <20180303002155.20689-2-decui@microsoft.com> (raw)
In-Reply-To: <20180303002155.20689-1-decui@microsoft.com>

The pci-hyperv driver's channel callback hv_pci_onchannelcallback() is not
really a hot path, so we don't need to mark it as a perf_device, meaning
with this patch all HV_PCIE channels' target_cpu will be CPU0.

This patch can help to avoid a potential ABBA deadlock in the busy loop
of Hyper-V PCI driver's hv_compose_msi_msg().

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: stable@vger.kernel.org
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/channel_mgmt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index c21020b69114..55ee5e87073a 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -71,7 +71,7 @@ static const struct vmbus_device vmbus_devs[] = {
 	/* PCIE */
 	{ .dev_type = HV_PCIE,
 	  HV_PCIE_GUID,
-	  .perf_device = true,
+	  .perf_device = false,
 	},
 
 	/* Synthetic Frame Buffer */
-- 
2.7.4

  reply	other threads:[~2018-03-03  0:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-03  0:22 [PATCH] Drivers: hv: vmbus: respect what we get from hv_get_synint_state() Dexuan Cui
2018-03-03  0:22 ` Dexuan Cui
2018-03-03  0:22 ` Dexuan Cui [this message]
2018-03-03  0:22   ` [PATCH] Drivers: hv: vmbus: do not mark HV_PCIE as perf_device Dexuan Cui

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