Re: [patches] powerpc 8xx dcbz problem

[Steven Munroe <munroesj@xxxxxxxxxx>]

Nathan Sidwell wrote:
> Steven Munroe wrote:
>
>> I am trying to explain the larger context. That inserting dynamic test
>> alter over the place is in general a bad idea.
>
> We are not adding dynamic checks 'all over the place'.  We're adding
> an additional check in the startup code where __cache_line_size is
> being set.
>
Mark did suggest that dynamic check was a better alternative then the
cpu-tuned libraries.  I think Mark understands the issues I have with this.
>> So yes the one time check in libc-start.c does not hurt your situation.
>> The dynamic __cache_line_size hurts my situation by its very existience.
>
> I don't see how the problem that __cache_line_size causes a noticeable
> degradation memset itself is relevant to the merits of this patch. 
> That's a preexisting issue.
>
>> So please don't assume that you can add dynamic tuning anywhere you want
>> or anytime you want. Becuase while you may solve your problem you will
>> invariable harm someone elses situation.
>
> I still don't understand what is being harmed by this patch.
>
I and not talking about "this" specific patch but the larger problem.