pthreads & dynamic memory in fbsd vs. the same in linux

[Coleman Kane]

Could you post the code too, perchance?


On Thu, 10 Feb 2005 10:55:04 +0200, Andriy Tkachuk <ant at emict.com> wrote:
> Hi folks.
> 
> I noticed the strange stick of pthreads (amount ~ 500)
> when allocating dynamic memory by malloc or new
> in my system:
> 
> > uname -a
> FreeBSD ant.emict.com 5.3-STABLE FreeBSD 5.3-STABLE #0: Wed Feb  9 17:30:11 EET 2005     ant at ant:/lin/fbsd_obj/usr/src/sys/ANT  i386
> 
> It's interesting that the same program behaves differently
> when it is compiled in linux and run on my fbsd machine in
> linux_base-7.1_7 .
> 
> > ldd test2-linux
> test2-linux:
>         libpthread.so.0 => /lib/libpthread.so.0 (0x28065000)
>         libstdc++-libc6.2-2.so.3 => /usr/lib/libstdc++-libc6.2-2.so.3 (0x2807c000)
>         libm.so.6 => /lib/libm.so.6 (0x280bf000)
>         libc.so.6 => /lib/libc.so.6 (0x280e1000)
>         /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x2804c000)
> > ldd a.out
> a.out:
>         libpthread.so.1 => /usr/lib/libpthread.so.1 (0x28075000)
>         libstdc++.so.4 => /usr/lib/libstdc++.so.4 (0x28099000)
>         libm.so.3 => /lib/libm.so.3 (0x2816b000)
>         libc.so.5 => /lib/libc.so.5 (0x28184000)
> 
> Each thread allocates the amount of memory by 10 bytes in loop.
> The number of iterations is specified in cmdline arg. The program
> prints the time each thread is spent allocating memory in loop.
> Let's look on results.
> 
> > ./a.out n 1000  # 1000 iterations of new operator. Every new allocates 10bytes.
> thread 0 created
> thread 1 created
> thread 2 created
> thread 3 created
> thread 4 created
> ...
> thread 497 created
> thread 498 created
> thread 499 created
> 0.001114
> 0.001022
> 0.001021
> 0.001011
> 0.001014
> 0.001010
> 0.001013
> 0.001050
> 0.001035
> 0.001011
> 0.001013
> 0.001010
> 0.001013
> 0.001010
> 0.001029
> 0.001075
> 0.001053
> 0.001011
> 0.001014
> 0.001011
> 0.001030
> 0.001010
> 0.001015
> 0.001042
> 0.001019
> 0.001011
> 0.001014
> 0.001012
> 0.001013
> 0.001010
> 0.001014
> 0.361604
> 3.225090
> 3.225458
> 3.225696
> 3.225925
> 3.226152
> 3.226380
> 3.226608
> 3.226833
> 3.227062
> 3.227290
> 3.227517
> 3.227744
> 3.227972
> 3.228202
> 3.228451
> 3.228681
> 3.228912
> 3.229140
> 3.229367
> 
> The same, but in linux_base-7.1_7 :
> 
> > ./test2-linux n 1000
> thread 0 created
> thread 1 created
> ...
> thread 498 created
> thread 499 created
> 0.000467
> 0.000403
> 0.000402
> ...
> 0.000391
> 0.000391
> 0.000395
> ...
> 0.000395
> 0.010564
> 0.000398
> 0.000394
> 
> The program source is attached.
> 
> In linux program is compiled by
> $ gcc -v
> Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs
> gcc version 2.96 20000731 (Red Hat Linux 7.1 2.96-98)
> 
> in fbsd:
> > gcc -v
> Using built-in specs.
> Configured with: FreeBSD/i386 system compiler
> Thread model: posix
> gcc version 3.4.2 [FreeBSD] 20040728
> 
> 
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> 
>