pcistub_device_alloc() is never called in atomic context. The call chain ending up at pcistub_device_alloc() is:  pcistub_device_alloc() <- pcistub_seize() <- pcistub_probe() pcistub_probe() is only set as ".probe" in struct pci_driver. This function is not called in atomic context.
Despite never getting called from atomic context, pcistub_device_alloc() calls kzalloc() with GFP_ATOMIC, which does not sleep for allocation. GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, which can sleep and improve the possibility of sucessful allocation. Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> --- drivers/xen/xen-pciback/pci_stub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index 9e480fd..fecc536 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -71,7 +71,7 @@ static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev) dev_dbg(&dev->dev, "pcistub_device_alloc\n"); - psdev = kzalloc(sizeof(*psdev), GFP_ATOMIC); + psdev = kzalloc(sizeof(*psdev), GFP_KERNEL); if (!psdev) return NULL; -- 1.9.1