Re: [PATCH v4 4/4] meson: Warn when TCI is selected but TCG backend is available

[Philippe Mathieu-Daudé]

On 1/25/21 5:47 PM, Daniel P. Berrangé wrote:
> On Mon, Jan 25, 2021 at 03:45:30PM +0100, Philippe Mathieu-Daudé wrote:
>> Some new users get confused with 'TCG' and 'TCI', and enable TCI
>> support expecting to enable TCG.
>>
>> Emit a warning when native TCG backend is available on the
>> host architecture, mentioning this is a suboptimal configuration.
>>
>> Reviewed-by: Stefan Weil <sw@weilnetz.de>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
> 
> Nitpick, the text printed is completely rewritten from what they
> reviewed, so I would probably have dropped their R-b for that
> scenario.

I thought about it, and assumed their review tag was for the logical
change of adding a warning, not particularly the warning content.

I agree this it would have been better to ask them to review again.
Next time I will reset the tags.

>> Suggested-by: Daniel Berrangé <berrange@redhat.com>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  meson.build | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/meson.build b/meson.build
>> index 16b2560e7e7..f675c54e636 100644
>> --- a/meson.build
>> +++ b/meson.build
>> @@ -228,6 +228,13 @@
>>      else
>>        error('Unsupported CPU @0@, try --enable-tcg-interpreter'.format(cpu))
>>      endif
>> +  elif get_option('tcg_interpreter')
>> +    warning('Use of the TCG interpretor is not recommended on this host')
>> +    warning('architecture. There is a native TCG execution backend 
>> available')
>> +    warning('which provides substantially better performance and 
>> reliability.')
>> +    warning('It is strongly recommended to remove the 
>> --enable-tcg-interpreter')
>> +    warning('configuration option on this architecture to use the native')
>> +    warning('backend.')
>>    endif
>>    if get_option('tcg_interpreter')
>>      tcg_arch = 'tci'
>> -- 
>> 2.26.2
>>
> 
> Regards,
> Daniel
>