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

[Sepherosa Ziehau]

On Mon, Sep 12, 2016 at 4:39 PM, Sepherosa Ziehau <sephe at freebsd.org> wrote:
> On Mon, Sep 12, 2016 at 4:32 PM, Konstantin Belousov
> <kostikbel at gmail.com> wrote:
>> 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 ?
>
> Nope, I am about to try it now.  BTW, I just checked the code for
> ACPI_DMAR, I didn't see anything obviously w/ the lock type change
> though.

I didn't notice anything wrong w/ options
ACPI_DMAR+WITNESS+INVARIANTS.  If you saw anything wrong, please let
me know.

Thanks,
sephe

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