Android and compatibility with deprecated armv7 instructions

[Mark Brown]

On Wed, Jul 02, 2014 at 06:01:41PM +0100, Will Deacon wrote:
> On Wed, Jul 02, 2014 at 05:39:23PM +0100, Mark Brown wrote:
> > On Wed, Jul 02, 2014 at 11:01:33AM +0100, Will Deacon wrote:

> > >   (1) The hardware doesn't have the instruction at all. If we start
> > >       emulating it, then we'll always have to emulate it and it doesn't
> > >       encourage software migration.

> > That's what the logging other architectures did in similar situations
> > was intended to help address - even if people don't care about the
> > performance impact having loud complaints in the logs tends to cause
> > some useful subset of users to report it as a problem.

> I don't think logging something to dmesg is going to make a blind bit of
> difference on an Android device. Maybe we could get SWP emulation to request

The same is true for the use cases this was being done for - you don't
need *every* user to notice, you need enough users to notice.

> Seriously though, nothing causes loud complaints like a SIGILL. This thread
> is evidence of that.

The trick is to make the complaints go to the application rather than
system vendor.
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