atomic changes break drm-next-kmod?

[John Baldwin]

On 7/3/18 3:40 PM, Matthew Macy wrote:
> This seems like a clang inline asm bug. Could you try building the port with a recent gcc against an unpatched HEAD?

I've already committed the patch to HEAD, but using 'e' is from the GCC docs, not clang docs:

https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html#Machine-Constraints

The disassembly of one of the functions from the kmod using one of the affected atomic ops would
show if it is working correctly (there should now be a mov with a 64-bit immediate into a register
followed by the atomic op using a register operand).  You could also try using just 'r' to always
force the use of a register.  It would be less optimal than "er" but should function correctly.

> On Tue, Jul 3, 2018 at 15:38 Pete Wright <pete at nomadlogic.org <mailto:pete at nomadlogic.org>> wrote:
> 
> 
> 
>     On 07/03/2018 15:29, John Baldwin wrote:
>     > That seems like kgdb is looking at the wrong CPU.  Can you use
>     > 'info threads' and look for threads not stopped in 'sched_switch'
>     > and get their backtraces?  You could also just do 'thread apply
>     > all bt' and put that file at a URL if that is easiest.
>     >
> 
> 
>     sure thing John - here's a gist of "thread apply all bt"
> 
>     https://gist.github.com/gem-pete/d8d7ab220dc8781f0827f965f09d43ed
> 
>     cheers!
>     -pete
> 
>     -- 
>     Pete Wright
>     pete at nomadlogic.org <mailto:pete at nomadlogic.org>
>     @nomadlogicLA
> 
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-- 
John Baldwin