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From: "Dan Stratila" <dstrat AT MIT DOT EDU>
To: <cygwin AT cygwin DOT com>
Subject: Re: malloc/new allocate twice as much?
Date: Fri, 30 Dec 2005 21:18:02 -0500
Message-ID: <000001c60db0$6e173e20$43055f12@somerville>
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From: Krzysztof Duleba <krzysan at skrzynka dot pl> 
To: cygwin at cygwin dot com 
Date: Sat, 31 Dec 2005 02:23:20 +0100 
Subject: Re: malloc/new allocate twice as much? 
References: <001e01c60d96$82fc34e0$43055f12 AT somerville> 

>>This is an issue I've discovered and reproduced while trying to compile
>>polymake (see the thread "gcc crash (memory?)"). It seems that both malloc
>>and new allocate take up twice the amount of memory needed.

>>I wrote a short program to allocate and use memory in chunks
(mem-test.cpp),
>>and compiled it with g++ 3.4.4. I monitored it using the Windows Task
>>Manager. When asked to allocate 100MB in increments of 10MB, the process
>>size goes to 100MB and then drops to 0, as expected. However, the total
>>commit charge for the machine goes up by 200MB, and then drops back!

>Try the snapshot. On my laptop with XP SP2, 20051222 snapshot, 1GB RAM 
>and 1GB swap file I had no problem allocating 1.8 GB.

Yes! This solved the malloc/new problem. Thanks. I sure hope the next
release of the cygwin dll will not reintroduce this bug... ;)

Now, I am also able to compile polymake, which required g++ to consume up to
600MB of RAM and caused it to crash when I was using the old dll with the
buggy malloc/new.

Dan



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