<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Indeed, I meant official released 3.5. Did you get your compiler from clang-omp.github? It's probably outdated and can't be used for reliable performance measurements.</div><div><br></div><div>I will update clang-omp.github home page to avoid further confusion.<br><br>Yours,<div>Andrey</div></div><div><br>19 авг. 2015 г., в 8:17, Bataev, Alexey <<a href="mailto:a.bataev@hotmail.com">a.bataev@hotmail.com</a>> написал(а):<br><br></div><blockquote type="cite"><div>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
If you're using 3.5, then this is unofficial version with OpenMP.
Use 3.7 instead just like Andrey said<br>
<pre class="moz-signature" cols="72">Best regards,
Alexey Bataev
=============
Software Engineer
Intel Compiler Team</pre>
<div class="moz-cite-prefix">19.08.2015 1:25, César via Openmp-dev
пишет:<br>
</div>
<blockquote cite="mid:CAHN8PecSVNQFHaTBaW3ej5c4TPPK_eyx-ODpzKXzSvqDuURD9g@mail.gmail.com" type="cite">
<div dir="ltr">Hi Andrey,
<div><br>
</div>
<div>this is strange because when I compile with "clang-3.5
-fopenmp" the executable that is produced is parallel. I am
sure of this because I'm able to see the threads and also
because I can see the symbols used by the IOMP runtime in the
binary.</div>
<div><br>
</div>
<div>$ clang -O3 -g -fopenmp toy13.cpp -o toy13 -lm<br>
</div>
<div><br>
</div>
<div>
<div>$ nm toy13 | grep kmpc</div>
<div>U __kmpc_cancel_barrier@@VERSION</div>
<div>U __kmpc_end_single@@VERSION</div>
<div>U __kmpc_fork_call@@VERSION</div>
<div>U __kmpc_omp_task_alloc@@VERSION</div>
<div>U __kmpc_omp_task_with_deps@@VERSION</div>
<div>U __kmpc_single@@VERSION</div>
<div><br>
</div>
<div>$ ldd toy13 </div>
<div>linux-vdso.so.1 => (0x00007fff9805d000)</div>
<div>libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6
(0x00007fc00e3cc000)</div>
<div>libiomp5.so => /usr/lib/libiomp5.so
(0x00007fc00e121000)</div>
<div>libpthread.so.0 =>
/lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fc00df03000)</div>
<div>libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
(0x00007fc00db3e000)</div>
<div>libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2
(0x00007fc00d939000)</div>
<div>/lib64/ld-linux-x86-64.so.2 (0x00007fc00e6fc000)</div>
</div>
<div><br>
</div>
<div><br>
</div>
<div class="gmail_extra"><br clear="all">
<div>
<div class="gmail_signature"><br>
<br>
César.</div>
</div>
<br>
<div class="gmail_quote">On Tue, Aug 18, 2015 at 6:15 PM, <span dir="ltr"><<a moz-do-not-send="true" href="mailto:andreybokhanko@gmail.com" target="_blank">andreybokhanko@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="auto">
<div>C<span style="background-color:rgba(255,255,255,0)">ésar,</span></div>
<div><br>
</div>
<div><span class="">
<blockquote type="cite">
<div dir="ltr">
<div><font color="#000000"><span style="background-color:rgba(255,255,255,0)">-
The version of Clang that I am using to
compile the benchmarks: 3.5.0</span></font></div>
</div>
</blockquote>
<div><br>
</div>
</span>Clang 3.5 doesn't support OpenMP -- it simply
ignores the pragmas.</div>
<div><br>
</div>
<div>Please use version from trunk or from 3_7 release
branch. Also, please supply -fopenmp= libomp option.</div>
<div><br>
</div>
<div>Yours,</div>
<div>Andrey Bokhanko</div>
<div>=============</div>
<div>Software Engineer</div>
<div>Intel Compiler Team</div>
<div>Intel</div>
<div><br>
Отправлено с iPad</div>
<div><br>
18 авг. 2015 г., в 21:14, César via Openmp-dev <<a moz-do-not-send="true" href="mailto:openmp-dev@lists.llvm.org" target="_blank"></a><a class="moz-txt-link-abbreviated" href="mailto:openmp-dev@lists.llvm.org">openmp-dev@lists.llvm.org</a>>
написал(а):<br>
<br>
</div>
<div>
<div class="h5">
<blockquote type="cite">
<div>
<div dir="ltr">Hello,
<div><br>
</div>
<div>I don't know if this is the correct list
to talk about this - I did not find a better
place..<br>
</div>
<div><br>
</div>
<div>I am doing performance experiments with a
few OpenMP implementations (IOMP, GOMP and
our private impl.) and I am seeing a severe
slowdown when I use IOMP (GOMP and others
are performing well). </div>
<div><br>
</div>
<div>The benchmarks I am using are these
ones: <a moz-do-not-send="true" href="http://kastors.gforge.inria.fr/#%21index.md" target="_blank">http://kastors.gforge.inria.fr/#!index.md</a><br clear="all">
</div>
<div><br>
</div>
<div>Really, the slowdown is huge. For one of
the programs (plasma/dpotrf_taskdep -n 8192
-b 64 -i 1 -c) the serial version executes
in ~28s and the parallel one executes in
~110s. I did some profiling and found that
most of the time is being spent on
synchronization barriers and dependence
tracking (see attached image). Before
digging deeper I would like to hear back
from you if I am doing something wrong here:</div>
<div><br>
</div>
<div>- I tested with the last version of the
repository: <a moz-do-not-send="true" href="http://llvm.org/svn/llvm-project/openmp/trunk" target="_blank">http://llvm.org/svn/llvm-project/openmp/trunk</a></div>
<div>
<div>
<div>- I am using Ubuntu 14.10.</div>
<div>- I have tested on more than one
machine, the results above are from a
Intel i7-3770</div>
<div>- The runtime itself is compiled
using: make compiler=gcc os_omp=linux
arch=32e</div>
<div>- The version of GCC that I am using
is: 4.9.1</div>
<div>- The version of Clang that I am
using to compile the benchmarks: 3.5.0</div>
<div><br>
<br>
César.</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
</div>
<blockquote type="cite">
<div><pic1.png></div>
</blockquote>
<span class="">
<blockquote type="cite">
<div><pic2.png></div>
</blockquote>
<blockquote type="cite">
<div><pic3.png></div>
</blockquote>
<blockquote type="cite">
<div><span>_______________________________________________</span><br>
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</div>
</blockquote>
</span></div>
</blockquote>
</div>
<br>
</div>
</div>
<br>
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