lkml.org 
[lkml]   [2019]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] VFIO: PCI: eliminate unnecessary overhead in vfio_pci_reflck_find
Date
From: Miaohe Lin <linmiaohe@huawei.com>

The driver of the pci device may not equal to vfio_pci_driver,
but we fetch vfio_device from pci_dev unconditionally in func
vfio_pci_reflck_find. This overhead, such as the competition
of vfio.group_lock, can be eliminated by check pci_dev_driver
with vfio_pci_driver first.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
drivers/vfio/pci/vfio_pci.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 379a02c36e37..1e21970543a6 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1466,15 +1466,14 @@ static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data)
struct vfio_device *device;
struct vfio_pci_device *vdev;

- device = vfio_device_get_from_dev(&pdev->dev);
- if (!device)
- return 0;
-
if (pci_dev_driver(pdev) != &vfio_pci_driver) {
- vfio_device_put(device);
return 0;
}

+ device = vfio_device_get_from_dev(&pdev->dev);
+ if (!device)
+ return 0;
+
vdev = vfio_device_data(device);

if (vdev->reflck) {
--
2.19.1
\
 
 \ /
  Last update: 2019-10-30 11:57    [W:0.056 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site