svn commit: r305722 - head/sys/x86/x86

[Konstantin Belousov]

On Mon, Sep 12, 2016 at 04:57:58AM +0000, Sepherosa Ziehau wrote:
> Author: sephe
> Date: Mon Sep 12 04:57:58 2016
> New Revision: 305722
> URL: https://svnweb.freebsd.org/changeset/base/305722
> 
> Log:
>   x86: Use sx lock for interrupt sources.
>   
>   - Certain pic_assign_cpu, e.g. msi_assign_cpu can have quite a long
>     call chain.  For msi_assign_cpu, mutex makes complex PCI bridge
>     drivers more tricky, e.g. sleep can note be called, etc, it will
>     be pretty tricky for upcoming Hyper-V PCI bridge driver for PCI
>     pass-through.

>   - It is not used on any hot code path nor non-sleepable context, so
>     sx should have the same effect as mutex.
Did you tested ACPI_DMAR interrupt remapping mode with your patch and
witness enabled ?

>   
>   PIC list is still protected by mutex to keep suspend/resume work.