On Thu, May 28, 2015 at 11:52 AM, David Miller [off-list ref] wrote:

From: Ben Hutchings <redacted>
Date: Wed, 27 May 2015 20:57:37 +0100

quoted

How would an application tell the difference between an IRQ handler
being renamed, or being unregistered and re-registered under a different
name?  I'm fairly sure it can't tell.

What do things like the userland IRQ balancer do?

Thanks to Neil Horman, userland scripts can get the irq number from
sysfs (/sys/bus/pci/devices/<device>/msi_irqs) which is not based on
the irq naming [1].
He also fixed irq_balancer [2] to use this API instead of being based
on those strings.

I will drop the irq renaming from the patchset. mlx5_core driver will
set generic irq names (since same irq's might service both Ethernet
and Infiniband), for example: mlx5_comp0@pci:0000:00:04.0.

Thanks,
Amir


[1] - kernel: da8d1c8 PCI/sysfs: add per pci device msi[x] irq listing (v5)
[2] - irq_balancer: 32a7757 Complete rework of how we detect and classify irqs