Re: Reduce libstdc++-v3 locale::locale() lock contention

[Paolo Carlini <paolo dot carlini at oracle dot com>]

On 12/17/2009 09:11 PM, Jimmy Guo wrote:
>>> Yes you are right.  Cannot do this without ABI breakage.  The old object
>>> handling destruction will cause problem.
>>>   
>>>       
>> Yeah, I also think so, unfortunately :( Would improve the performance a
>> lot, eh? Any idea how much?
>>     
> Indeed a lot ... so tempted to apply this to my custom gcc and ask all of
> our affected projects to rebuild their libraries ...
>
> a. Current:
> nthreads = 1: 1585
> nthreads = 2: 4501
> nthreads = 4: 26203
> nthreads = 8: 31745
>
> b. locale::locale() lock contention reduction:
> nthreads = 1: 1237
> nthreads = 2: 2028
> nthreads = 4: 8371
> nthreads = 8: 21262
>
> c. 'b' + C locale ref counting removal:
> nthreads = 1: 1159
> nthreads = 2: 1523
> nthreads = 4: 1742
> nthreads = 8: 1902
>   
I see, grunt.

For now I committed the below (tested x86_64-linux multilib) which will
probably remain our main improvement for 4.5.0, we'll see...

Thanks again,
Paolo.

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