From: "Liu, Yongxin" <Yongxin.Liu@windriver.com>
To: "Liu, Yongxin" <Yongxin.Liu@windriver.com>,
"dev@dpdk.org" <dev@dpdk.org>
Cc: "david.w.su@intel.com" <david.w.su@intel.com>,
"stephen@networkplumber.org" <stephen@networkplumber.org>,
"ferruh.yigit@intel.com" <ferruh.yigit@intel.com>,
"anuj.mittal@intel.com" <anuj.mittal@intel.com>,
"Hao, Kexin" <Kexin.Hao@windriver.com>,
"Yang, Liezhi" <Liezhi.Yang@windriver.com>
Subject: Re: [dpdk-dev] [RFC] igb_uio: change ISR to be threaded when using with RT kernel
Date: Fri, 20 Sep 2019 00:58:17 +0000 [thread overview]
Message-ID: <597B109EC20B76429F71A8A97770610D19E0837D@ALA-MBD.corp.ad.wrs.com> (raw)
In-Reply-To: <20190920004525.18259-1-yongxin.liu@windriver.com>
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
prev parent reply other threads:[~2019-09-20 0:58 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-20 0:45 Yongxin Liu
2019-09-20 0:58 ` Liu, Yongxin [this message]
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