[RFC] igb_uio: change ISR to be threaded when using with RT kernel
diff mbox series

Message ID 20190920004525.18259-1-yongxin.liu@windriver.com
State New
Delegated to: David Marchand
Headers show
Series
  • [RFC] igb_uio: change ISR to be threaded when using with RT kernel
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Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Liu, Yongxin Sept. 20, 2019, 12:45 a.m. UTC
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.liu@windriver.com>
---
 kernel/linux/igb_uio/igb_uio.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

Comments

Liu, Yongxin Sept. 20, 2019, 12:58 a.m. UTC | #1
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-bounces@dpdk.org] On Behalf Of Yongxin Liu
> Sent: Friday, September 20, 2019 08:45
> To: dev@dpdk.org
> Cc: david.w.su@intel.com; stephen@networkplumber.org;
> ferruh.yigit@intel.com; anuj.mittal@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.liu@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

Patch
diff mbox series

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;