Hi all,<br>Thanks Rob,<br><br>I have been reading MPI 2 book, and other materials, and i still be in doubt with some concepts.<br><br>There are some doubt topics that i havent learn yet.<br><br>These hints, they are effective only in non-contiguos situations, is it right?
<br>romio_pvfs_listio_write and read for example, they would be effective in non contiguous situations?<br><br>ROMIO excuses the necessity of build list_io_read function, when we use these above hints?<br><br>And talking about Non-contiguous access, i understood it as a heterogeneous thing. For example, in a data, we have the first 3 blocks of one type, and the next block is a different thing with 2 blocks for example. Is it right?
<br><br>Contiguity refers to belong to a same element?<br><br>When i define an MPI_Vector for example, i set non null strides. These blank spaces, they could be used for other elements?<br><br>I am trying to make a simple benchmark to measure bandwith, but i didnt get it works yet.
<br><br>Non contiguouos datatypes are only these ones that have strides? if i make a datatype that consists of a "entire line row" in each block, it could be considered a non contiguos thing? The hints would do any influency over it?
<br><br>In MPICH2, i create a mpd.hosts file, but i am not getting it works, mpdtrace doesnt tell anything about the slave node. What should i do?<br><br>Thanks in advance, luiz.<br><br><br><br><br><br><div><span class="gmail_quote">
2007/1/22, Rob Ross <<a href="mailto:rross@mcs.anl.gov">rross@mcs.anl.gov</a>>:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi Luiz,<br><br>That's exactly where the hints go. You can also use the<br>MPI_File_set_info() call if you like, and you can pass hints it at<br>MPI_File_set_view() time as well.<br><br>Regards,<br><br>Rob<br><br>Luiz Mendes wrote:
<br>> Hi all,<br>><br>> I have read MPI 2 book, ROMIO guide and some articles about<br>> optimizations for MPI IO. But i didnt see yet or i didnt understand<br>> where hints would be placed on MPI_File_open code.
<br>><br>> Should i use ROMIO hints replaceing MPI_INFO_NULL constant in<br>> MPI_File_open function?<br>><br>> Thanks in advance<br>> Luiz Mendes<br>><br>><br></blockquote></div><br>