cvs commit: src/lib/libc/stdlib malloc.c

[Scott Long]

Jason Evans wrote:
> On Jan 26, 2006, at 6:51 PM, Andrey Chernov wrote:
> 
>> I worry about my system performance. Could you please make all  
>> statistics
>> and debug code conditional, debending on some flags which could be  
>> set as
>> malloc options? Even in case this is a test period now, some people
>> perhaps don't want some tests. It is much easy to turn some tests  off 
>> via
>> malloc options than to comment out manually corresponding malloc.c  
>> defines
>> after each cvsup.
> 
> 
> Unfortunately, run-time checks for the debugging features are  
> expensive, since the debugging code is scattered throughout  malloc.c.  
> This pretty much mandates compile-time configuration, for  performance 
> reasons.
> 
> I can disable statistics and debugging, if there's a general  consensus 
> to do so.  How much performance difference is the debug/ stats code 
> making for you?  I've only been disabling debug/stats for  benchmarking 
> purposes, so I don't have a good feel for how much it  impacts overall 
> system performance.
> 
> Thanks,
> Jason
> 

I think that it's all just fine the way it is.  If you can refactor 
things so that it's convenient and non-intrusive to make the debugging
controllable at runtime, that's great, but it's not something to loose
sleep over.

Scott