From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:36246 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933514AbeF2PjP (ORCPT ); Fri, 29 Jun 2018 11:39:15 -0400 Date: Fri, 29 Jun 2018 16:41:01 +0100 From: Lorenzo Pieralisi To: Jia-Ju Bai Cc: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, bhelgaas@google.com, devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] pci: host: pci-hyperv: Replace GFP_ATOMIC with GFP_KERNEL in new_pcichild_device Message-ID: <20180629154101.GI9643@red-moon> References: <1521384808-23627-1-git-send-email-baijiaju1990@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1521384808-23627-1-git-send-email-baijiaju1990@gmail.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Sun, Mar 18, 2018 at 10:53:28PM +0800, Jia-Ju Bai wrote: > 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 > --- > drivers/pci/host/pci-hyperv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Applied to pci/hv for v4.19, thanks. Lorenzo > 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 >