> -----Original Message----- > From: linux-kernel-owner@xxxxxxxxxxxxxxx <linux-kernel-owner@xxxxxxxxxxxxxxx> On Behalf > Of Jia-Ju Bai > Sent: Sunday, March 18, 2018 7:53 AM > To: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; Stephen > Hemminger <sthemmin@xxxxxxxxxxxxx>; bhelgaas@xxxxxxxxxx > Cc: devel@xxxxxxxxxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > Jia-Ju Bai <baijiaju1990@xxxxxxxxx> > Subject: [PATCH 2/2] pci: host: pci-hyperv: Replace GFP_ATOMIC with GFP_KERNEL in > new_pcichild_device > > new_pcichild_device() is not called in atomic context. > > The call chain ending up at new_pcichild_device() is: > [1] new_pcichild_device() <- pci_devices_present_work() > pci_devices_present_work() is only set in INIT_WORK(). > > Despite never getting called from atomic context, > new_pcichild_device() calls kzalloc with GFP_ATOMIC, > which waits busily for allocation. > GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL > to avoid busy waiting. > > This is found by a static analysis tool named DCNS written by myself. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> > --- > drivers/pci/host/pci-hyperv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c > index 0fe3ea1..289e31d 100644 > --- a/drivers/pci/host/pci-hyperv.c > +++ b/drivers/pci/host/pci-hyperv.c > @@ -1500,7 +1500,7 @@ static struct hv_pci_dev *new_pcichild_device(struct > hv_pcibus_device *hbus, > unsigned long flags; > int ret; > > - hpdev = kzalloc(sizeof(*hpdev), GFP_ATOMIC); > + hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL); > if (!hpdev) > return NULL; > > -- > 1.9.1
