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Re: calloc speed difference




On 1/12/18, Corinna Vinschen  wrote:
> On Jan 12 15:06, Christian Franke wrote:
>> Lee wrote:
>> > Why is the cygwin gcc calloc so much slower than the
>> > i686-w64-mingw32-gcc calloc?
>> >    1:12 vs 0:11
    <.. snip example prog ..>
>>
>> Could reproduce the difference on an older i7-2600K machine:
>>
>> Cygwin: ~20s
>> MinGW: ~4s
     <.. snip possible explanation ..>
>
> But then again, Cygwin's malloc *is* slow, particulary in
> memory-demanding multi-threaded scenarios since that serializes all
> malloc/free calls.
>
> The memory handling within Cygwin is tricky.  Attempts to replace good
> old dlmalloc with a fresher jemalloc or ptmalloc failed, but that only
> means the developer (i.e., me, in case of ptmalloc) was too lazy...
> busy! I mean busy... to pull this through.
>
> Having said that, if somebody would like to take a stab at replacing
> dlmalloc with something leaner, I would be very happy and assist as
> much as I can.

I just took a quick look at some malloc code & docs and I know enough
to know that I'm not going to be the one taking a stab at replacing
dlmalloc.  Sorry :(

Lee

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