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    <title>topic MKL Sparse BLAS segfaults due to integer overflow in Intel® oneAPI Math Kernel Library</title>
    <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073937#M22430</link>
    <description>&lt;P&gt;Hello&lt;/P&gt;

&lt;P&gt;I am a very recent user of Intel MKL. I was trying to use Sparse BLAS library (Inspector/Executor routines), when I ran into an obscure segfault. The segfault appeared in CSR matrix transpose operations, and only when the number of rows was large enough (roughly 100M). Here is a more detailed description that I posted on stackoverflow.com: &lt;A href="http://stackoverflow.com/questions/37395541/mkl-sparse-blas-segfault-when-transposing-csr-with-100m-rows" target="_blank"&gt;http://stackoverflow.com/questions/37395541/mkl-sparse-blas-segfault-when-transposing-csr-with-100m-rows&lt;/A&gt; .&lt;/P&gt;

&lt;P&gt;Eventually I was able to track it down to obvious integer overflow, while computing memory size for malloc (number of rows is getting multiplied by the number of threads, which was 32 in my case).&lt;/P&gt;

&lt;P&gt;It took me a couple of days, so I keep wondering&lt;/P&gt;

&lt;OL&gt;
	&lt;LI&gt;&lt;SPAN style="font-size: 13.008px; line-height: 19.512px;"&gt;Did I miss some relevant&amp;nbsp;part of MKL documenation? An explanation about maximum feasible number of rows in a sparse matrix seems essential. Spending time to figure it out from gdb disas somehow doesn't feel right.&lt;/SPAN&gt;&lt;/LI&gt;
	&lt;LI&gt;&lt;SPAN style="font-size: 13.008px; line-height: 19.512px;"&gt;Regardless, it sure feels like a bug. I would expect &lt;/SPAN&gt;&lt;SPAN class="s1"&gt;mkl_sparse_convert_csr to return an error status instead of crashing.&lt;/SPAN&gt;&lt;SPAN style="font-size: 13.008px; line-height: 19.512px;"&gt;&amp;nbsp;&lt;/SPAN&gt;&lt;/LI&gt;
&lt;/OL&gt;

&lt;P&gt;Is it a known issue? Are there any other known limits here that I should be aware of?&lt;/P&gt;</description>
    <pubDate>Wed, 25 May 2016 19:03:36 GMT</pubDate>
    <dc:creator>Alexander_G_2</dc:creator>
    <dc:date>2016-05-25T19:03:36Z</dc:date>
    <item>
      <title>MKL Sparse BLAS segfaults due to integer overflow</title>
      <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073937#M22430</link>
      <description>&lt;P&gt;Hello&lt;/P&gt;

&lt;P&gt;I am a very recent user of Intel MKL. I was trying to use Sparse BLAS library (Inspector/Executor routines), when I ran into an obscure segfault. The segfault appeared in CSR matrix transpose operations, and only when the number of rows was large enough (roughly 100M). Here is a more detailed description that I posted on stackoverflow.com: &lt;A href="http://stackoverflow.com/questions/37395541/mkl-sparse-blas-segfault-when-transposing-csr-with-100m-rows" target="_blank"&gt;http://stackoverflow.com/questions/37395541/mkl-sparse-blas-segfault-when-transposing-csr-with-100m-rows&lt;/A&gt; .&lt;/P&gt;

&lt;P&gt;Eventually I was able to track it down to obvious integer overflow, while computing memory size for malloc (number of rows is getting multiplied by the number of threads, which was 32 in my case).&lt;/P&gt;

&lt;P&gt;It took me a couple of days, so I keep wondering&lt;/P&gt;

&lt;OL&gt;
	&lt;LI&gt;&lt;SPAN style="font-size: 13.008px; line-height: 19.512px;"&gt;Did I miss some relevant&amp;nbsp;part of MKL documenation? An explanation about maximum feasible number of rows in a sparse matrix seems essential. Spending time to figure it out from gdb disas somehow doesn't feel right.&lt;/SPAN&gt;&lt;/LI&gt;
	&lt;LI&gt;&lt;SPAN style="font-size: 13.008px; line-height: 19.512px;"&gt;Regardless, it sure feels like a bug. I would expect &lt;/SPAN&gt;&lt;SPAN class="s1"&gt;mkl_sparse_convert_csr to return an error status instead of crashing.&lt;/SPAN&gt;&lt;SPAN style="font-size: 13.008px; line-height: 19.512px;"&gt;&amp;nbsp;&lt;/SPAN&gt;&lt;/LI&gt;
&lt;/OL&gt;

&lt;P&gt;Is it a known issue? Are there any other known limits here that I should be aware of?&lt;/P&gt;</description>
      <pubDate>Wed, 25 May 2016 19:03:36 GMT</pubDate>
      <guid>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073937#M22430</guid>
      <dc:creator>Alexander_G_2</dc:creator>
      <dc:date>2016-05-25T19:03:36Z</dc:date>
    </item>
    <item>
      <title>Alexander, thanks for the</title>
      <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073938#M22431</link>
      <description>&lt;P&gt;Alexander, thanks for the issue. We will check this on our side, but meantime, could you try ILP64 API?&amp;nbsp;&lt;/P&gt;</description>
      <pubDate>Thu, 26 May 2016 14:08:09 GMT</pubDate>
      <guid>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073938#M22431</guid>
      <dc:creator>Gennady_F_Intel</dc:creator>
      <dc:date>2016-05-26T14:08:09Z</dc:date>
    </item>
    <item>
      <title>Alexander, I see ( http:/</title>
      <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073939#M22432</link>
      <description>&lt;P&gt;Alexander, I see ( &lt;A href="http://stackoverflow.com/questions/37395541/mkl-sparse-blas-segfault-when-transposing-csr-with-100m-rows&amp;nbsp;)" target="_blank"&gt;http://stackoverflow.com/questions/37395541/mkl-sparse-blas-segfault-when-transposing-csr-with-100m-rows&amp;nbsp;)&lt;/A&gt; one &amp;nbsp;of my colleague, have checked the problem with latest 11.3.2 and recommended to play with ILP64 also.&amp;nbsp;&lt;/P&gt;</description>
      <pubDate>Sun, 29 May 2016 04:23:13 GMT</pubDate>
      <guid>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/MKL-Sparse-BLAS-segfaults-due-to-integer-overflow/m-p/1073939#M22432</guid>
      <dc:creator>Gennady_F_Intel</dc:creator>
      <dc:date>2016-05-29T04:23:13Z</dc:date>
    </item>
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