Re: [PATCH v7 3/6] igb_uio: fix MSI-X IRQ assignment with new IRQ function

On Mon, Sep 11, 2017 at 03:04:01PM -0700, Stephen Hemminger wrote:

I wonder if it is time to move the bar forward to oldest LTS which is
3.2.92

That seems reasonable. Probably best to do a deprecation notice for it
in 17.11 and move the bar in 18.02.

/Bruce

On Sep 11, 2017 10:56 AM, "Ferruh Yigit" [off-list ref] wrote:

quoted

On 9/5/2017 1:04 PM, Markus Theil wrote:

quoted

The patch which introduced the usage of pci_alloc_irq_vectors
came after the patch which switched to non-threaded ISR (f0d1896fa1),
but did not use non-threaded ISR, if pci_alloc_irq_vectors
is used.

Fixes: 99bb58f3adc7 ("igb_uio: switch to new irq function for
MSI-X")
Cc: nicolas.dichtel@6wind.com

Signed-off-by: Markus Theil <redacted>
---
 lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c

b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c

quoted

index 93bb71d..6885e72 100644

--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c

@@ -331,6 +331,7 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev

*udev)

quoted

 #else
              if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX)

== 1) {

quoted

                      dev_dbg(&udev->pdev->dev, "using MSI-X");
+                     udev->info.irq_flags = IRQF_NO_THREAD;

IRQF_NO_THREAD seems has been introduced in 2.6.39, so using this flag
causing build error for kernel versions < 2.6.39.

btw, the flag is already in use, so issue is not related to this patch.

In DPDK documentation supported Linux kernel version is >= 2.6.34 [1].

We should either increase supported version to 2.6.39, or update igb_uio
code.

I am for increasing minimum supported kernel version to 2.6.39, any
objection / comment?

2.6.39 released on May 2011
2.6.34 released on May 2010


[1]
http://dpdk.org/doc/guides/linux_gsg/sys_reqs.html#system-software

quoted

                      udev->info.irq = pci_irq_vector(udev->pdev, 0);
                      udev->mode = RTE_INTR_MODE_MSIX;
                      break;