mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-02 10:59:18 -04:00
9ea69a55b3
With virtio multiqueue, normally each queue IRQ is mapped to a CPU. Commit0d9f0a52c8("virtio_scsi: use virtio IRQ affinity") exposed an existing shortcoming of the arch code by moving virtio_scsi to the automatic IRQ affinity assignment. The affinity is correctly computed in msi_desc but this is not applied to the system IRQs. It appears the affinity is correctly passed to rtas_setup_msi_irqs() but lost at this point and never passed to irq_domain_alloc_descs() (see commit06ee6d571f("genirq: Add affinity hint to irq allocation")) because irq_create_mapping() doesn't take an affinity parameter. Use the new irq_create_mapping_affinity() function, which allows to forward the affinity setting from rtas_setup_msi_irqs() to irq_domain_alloc_descs(). With this change, the virtqueues are correctly dispatched between the CPUs on pseries. Fixes:e75eafb9b0("genirq/msi: Switch to new irq spreading infrastructure") Signed-off-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kurz <groug@kaod.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201126082852.1178497-3-lvivier@redhat.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.