| |
|
 |
|
 |
|
|
|
| |
|
|
xen-ia64-devel
RE: [Xen-ia64-devel] RE: in_tpa is not SMP-safe
> > I was hoping Kevin would respond to this as my memory
> > on it is dim. There was a rare but significant problem
> > that this code was fixing and we went through several
> > attempts to fix it. I don't think we ever understood
> > exactly why this code was necessary because we (both
> > Kevin and I) thought a different code sequence should
> > work, but it didn't.
> >
> > So, yes, make the change to make it SMP-safe (I prefer
> > the parameter), but be careful about changing the
> > "in_tpa" semantics without running a very thorough
> > test suite.
> Ok.
>
> Also, vcpu_translate look in itr_regions even for
> data_access. There is a
> comment about that:
> // FIXME?: check itr's for data accesses too, else bad things happen?
> I suppose this is required to read instructions from Xen.
> Are there any other
> uses ? Is it too dangerous to try to fix that ?
It is certainly dangerous to change any of this code. I spent
several days playing with it (to improve performance) last
October and was often surprised when a change broke everything.
I definitely tried to fix the specific code you are referring
to but never got it to work, ran out of time, and gave up.
If you do try any changes, make sure it is tested VERY thoroughly
as sometimes the problems I saw only showed up infrequently
(e.g. compiling Linux failed 10 in 20 times instead of just 1
in 20 times).
Dan
_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel
|
|
|
| |
|
Home