Hi DPDK experts, This patch is especially used for PREEMPT_RT kernel. Whether it is correct, please share your opinion.
Thanks, Yongxin > -----Original Message----- > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Yongxin Liu > Sent: Friday, September 20, 2019 08:45 > To: dev@dpdk.org > Cc: david.w...@intel.com; step...@networkplumber.org; > ferruh.yi...@intel.com; anuj.mit...@intel.com; Hao, Kexin; Yang, Liezhi > Subject: [dpdk-dev] [RFC] igb_uio: change ISR to be threaded when using > with RT kernel > > When igb_uio driver is used with RT kernel, the interrupt handler > should not use IRQF_NO_THREAD as a flag, since uio_event_notify will > call rt_spin_lock which might sleep. > > Here is the calltrace. > > [ 2034.457805] Call Trace: > [ 2034.460818] <IRQ> > [ 2034.463397] dump_stack+0x70/0x9a > [ 2034.467281] ___might_sleep.cold+0xe1/0xf2 > [ 2034.471943] rt_spin_lock+0x55/0x70 > [ 2034.475994] ? __wake_up_common_lock+0x61/0xb0 > [ 2034.481004] __wake_up_common_lock+0x61/0xb0 > [ 2034.485842] __wake_up+0x13/0x20 > [ 2034.489635] uio_event_notify+0x2c/0x50 [uio] > [ 2034.494560] igbuio_pci_irqhandler+0x1f/0x40 [igb_uio] > [ 2034.500262] __handle_irq_event_percpu+0x5f/0x3f0 > [ 2034.505532] ? cpuidle_enter_state+0xd3/0x500 > [ 2034.510454] handle_irq_event_percpu+0x4b/0x90 > [ 2034.515462] handle_irq_event+0x3c/0x5b > [ 2034.519864] handle_edge_irq+0xbb/0x210 > [ 2034.524264] handle_irq+0x23/0x30 > [ 2034.528143] do_IRQ+0x7e/0x150 > [ 2034.531764] common_interrupt+0xf/0xf > [ 2034.535990] </IRQ> > > Signed-off-by: Yongxin Liu <yongxin....@windriver.com> > --- > kernel/linux/igb_uio/igb_uio.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/kernel/linux/igb_uio/igb_uio.c > b/kernel/linux/igb_uio/igb_uio.c > index 039f5a5f6..9d7380fb7 100644 > --- a/kernel/linux/igb_uio/igb_uio.c > +++ b/kernel/linux/igb_uio/igb_uio.c > @@ -221,7 +221,6 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev > *udev) > msix_entry.entry = 0; > if (pci_enable_msix(udev->pdev, &msix_entry, 1) == 0) { > dev_dbg(&udev->pdev->dev, "using MSI-X"); > - udev->info.irq_flags = IRQF_NO_THREAD; > udev->info.irq = msix_entry.vector; > udev->mode = RTE_INTR_MODE_MSIX; > break; > @@ -229,7 +228,6 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev > *udev) > #else > if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX) == > 1) { > dev_dbg(&udev->pdev->dev, "using MSI-X"); > - udev->info.irq_flags = IRQF_NO_THREAD; > udev->info.irq = pci_irq_vector(udev->pdev, 0); > udev->mode = RTE_INTR_MODE_MSIX; > break; > @@ -241,7 +239,6 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev > *udev) > #ifndef HAVE_ALLOC_IRQ_VECTORS > if (pci_enable_msi(udev->pdev) == 0) { > dev_dbg(&udev->pdev->dev, "using MSI"); > - udev->info.irq_flags = IRQF_NO_THREAD; > udev->info.irq = udev->pdev->irq; > udev->mode = RTE_INTR_MODE_MSI; > break; > @@ -249,7 +246,6 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev > *udev) > #else > if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSI) == 1) > { > dev_dbg(&udev->pdev->dev, "using MSI"); > - udev->info.irq_flags = IRQF_NO_THREAD; > udev->info.irq = pci_irq_vector(udev->pdev, 0); > udev->mode = RTE_INTR_MODE_MSI; > break; > @@ -259,7 +255,7 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev > *udev) > case RTE_INTR_MODE_LEGACY: > if (pci_intx_mask_supported(udev->pdev)) { > dev_dbg(&udev->pdev->dev, "using INTX"); > - udev->info.irq_flags = IRQF_SHARED | IRQF_NO_THREAD; > + udev->info.irq_flags = IRQF_SHARED; > udev->info.irq = udev->pdev->irq; > udev->mode = RTE_INTR_MODE_LEGACY; > break; > -- > 2.14.4
