Re: [Qemu-devel] [PATCH for-2.11 2/6] ppc: make cpu_model translation to type consistent

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Aug 25, 2017 at 04:34:26PM +0200, Igor Mammedov wrote:
> On Fri, 25 Aug 2017 23:28:00 +1000
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > On Fri, Aug 25, 2017 at 01:40:07PM +0200, Igor Mammedov wrote:
> > > On Fri, 25 Aug 2017 19:45:38 +1000
> > > David Gibson <david@gibson.dropbear.id.au> wrote:
> > >   
> > > > On Fri, Aug 25, 2017 at 09:27:40AM +0200, Igor Mammedov wrote:  
> > > > > On Fri, 25 Aug 2017 11:38:19 +1000
> > > > > David Gibson <david@gibson.dropbear.id.au> wrote:
> > > > >     
> > > > > > On Thu, Aug 24, 2017 at 10:21:47AM +0200, Igor Mammedov wrote:    
> > > > > > > PPC handles -cpu FOO rather incosistently,
> > > > > > > i.e. it does case-insensitive matching of FOO to
> > > > > > > a CPU type (see: ppc_cpu_compare_class_name) but
> > > > > > > handles alias names as case-sensitive, as result:
> > > > > > > 
> > > > > > >  # qemu-system-ppc64 -M mac99 -cpu g3
> > > > > > >  qemu-system-ppc64: unable to find CPU model ' kN�U'
> > > > > > > 
> > > > > > >  # qemu-system-ppc64 -cpu 970MP_V1.1
> > > > > > >  qemu-system-ppc64: Unable to find sPAPR CPU Core definition
> > > > > > > 
> > > > > > > while
> > > > > > > 
> > > > > > >  # qemu-system-ppc64 -M mac99 -cpu G3
> > > > > > >  # qemu-system-ppc64 -cpu 970MP_v1.1
> > > > > > > 
> > > > > > > start up just fine.
> > > > > > > 
> > > > > > > Considering we can't take case-insensitive matching away,
> > > > > > > make it case-insensitive for  all alias/type/core_type
> > > > > > > lookups.
> > > > > > > 
> > > > > > > As side effect it allows to remove duplicate core types
> > > > > > > which are the same but use lower-case letters in name.
> > > > > > > 
> > > > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com>      
> > > > > > 
> > > > > > Hmm.  So, I'm certainly good with making the matching more consistent,
> > > > > > and removing extra entries differing only in case.
> > > > > > 
> > > > > > However, I don't like capitalizing everything in the model table.  The
> > > > > > "canonical" capitalization - as in how it appears in manuals and
> > > > > > marketing info - is quite frequently mixed case.  So I think making
> > > > > > everything caps in the table will make it harder to read in the
> > > > > > context of looking at the corresponding documentation.    
> > > > > only cpu models => typenames are made caps, the rest    
> > > > 
> > > > Yes, I know.  A number of the CPU model names themselves have mixed
> > > > case.  Really.
> > > >   
> > > > > incl. description is kept as is in mixed case.
> > > > > It looks like _desc is the thing one would use for
> > > > > 1:1 lookup in spec, while _name isn't direct match consistently
> > > > > (i.e. sometimes it skips spaces and sometimes spaces are replaced by underscore).
> > > > > So keeping _name in mixed case unnecessarily complicates name->type lookup.
> > > > > 
> > > > > These mixed case + case-insensitive is what made lookup
> > > > > code over-engineered and overly complex.    
> > > > 
> > > > I'm fine with making all the lookups case insensitive.  I just don't
> > > > want to drop the case on the names in the actual code.  
> > > I've tried to find a way but considering that names are statically
> > > 'converted' into typenames and lack of ability to magically
> > > uppercase them with preprocessor, I've gave up on this approach.  
> > 
> > Ok.
> > 
> > > Providing that there is _desc with model name that should be
> > > greppable in spec and complexity of lookup code that mixed-cased
> > > typenames incur, I've opted in favor of simplifying lookup
> > > code at expense uniform typenames (which is inter QEMU thingy).
> > > It is easier to maintain and less chances to make mistake.  
> > 
> > Yeah, I guess.  It just looks weird to have non-standard capsing in
> > the table field.
> > 
> > Any chance we could standardize on lowercase rather than upper - for
> > some reason that would seem less odd to me (I guess because C-ish
> > names and identifiers are usually lowercased).
> The only reason I've picked up uppercase is that diffstat is smaller
> then with lowercase.
> So if you prefer lowercase, I'll switch case in v2.

Please do, thanks.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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