Hi Stephen, > -----Original Message----- > From: Stephen Hemminger [mailto:stephen at networkplumber.org] > Sent: Tuesday, January 27, 2015 6:00 PM > To: Xie, Huawei > Cc: Ouyang, Changchun; dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v2 04/24] virtio: Add support for Link State > interrupt > > On Tue, 27 Jan 2015 09:04:07 +0000 > "Xie, Huawei" <huawei.xie at intel.com> wrote: > > > > -----Original Message----- > > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Ouyang > > > Changchun > > > Sent: Tuesday, January 27, 2015 10:36 AM > > > To: dev at dpdk.org > > > Subject: [dpdk-dev] [PATCH v2 04/24] virtio: Add support for Link > > > State interrupt > > > > > > Virtio has link state interrupt which can be used. > > > > > > Signed-off-by: Stephen Hemminger <stephen at networkplumber.org> > > > Signed-off-by: Changchun Ouyang <changchun.ouyang at intel.com> > > > --- > > > lib/librte_pmd_virtio/virtio_ethdev.c | 78 > > > +++++++++++++++++++++++++++------ > > > -- > > > lib/librte_pmd_virtio/virtio_pci.c | 22 ++++++++++ > > > lib/librte_pmd_virtio/virtio_pci.h | 4 ++ > > > 3 files changed, 86 insertions(+), 18 deletions(-) > > > > > > diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c > > > b/lib/librte_pmd_virtio/virtio_ethdev.c > > > index 5df3b54..ef87ff8 100644 > > > --- a/lib/librte_pmd_virtio/virtio_ethdev.c > > > +++ b/lib/librte_pmd_virtio/virtio_ethdev.c > > > @@ -845,6 +845,34 @@ static int virtio_resource_init(struct > > > rte_pci_device *pci_dev __rte_unused) #endif > > > > > > /* > > > + * Process Virtio Config changed interrupt and call the callback > > > + * if link state changed. > > > + */ > > > +static void > > > +virtio_interrupt_handler(__rte_unused struct rte_intr_handle *handle, > > > + void *param) > > > +{ > > > + struct rte_eth_dev *dev = param; > > > + struct virtio_hw *hw = > > > + VIRTIO_DEV_PRIVATE_TO_HW(dev->data->dev_private); > > > + uint8_t isr; > > > + > > > + /* Read interrupt status which clears interrupt */ > > > + isr = vtpci_isr(hw); > > > + PMD_DRV_LOG(INFO, "interrupt status = %#x", isr); > > > + > > > + if (rte_intr_enable(&dev->pci_dev->intr_handle) < 0) > > > + PMD_DRV_LOG(ERR, "interrupt enable failed"); > > > + > > > > Is it better to put rte_intr_enable after we have handled the interrupt. > > Is there the possibility of interrupt reentrant in uio intr framework? > > The UIO framework handles IRQ's via posix thread that is reading fd, then > calling this code. Therefore it is always single threaded.
Even if it is under UIO framework, and always single threaded, How about move rte_intr_enable after the virtio_dev_link_update() and _rte_eth_dev_callback_process is called. This make it more like interrupt handler in linux kernel. What do you think of it? Thanks Changchun