<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Helvetica;
panose-1:2 11 6 4 2 2 2 2 2 4;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Intel Clear";
panose-1:2 11 6 4 2 2 3 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Intel Clear",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Intel Clear",sans-serif;color:#1F497D">That limitation is why MPI_WIN_CREATE_DYNAMIC was created…<o:p></o:p></span></p>
<p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Intel Clear",sans-serif;color:#1F497D"><o:p> </o:p></span></a></p>
<div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><a name="_____replyseparator"></a><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> mpiwg-rma [mailto:mpiwg-rma-bounces@lists.mpi-forum.org]
<b>On Behalf Of </b>William Gropp<br>
<b>Sent:</b> Tuesday, January 02, 2018 3:19 PM<br>
<b>To:</b> MPI WG Remote Memory Access working group <mpiwg-rma@lists.mpi-forum.org><br>
<b>Cc:</b> MPI WG Remote Memory Access working group <mpiwg-rma@mpi-forum.org><br>
<b>Subject:</b> Re: [mpiwg-rma] MPI_Win_create on unmapped memory?<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It was certainly the intent that the memory be allocated. Specifically, if a is the pointer and the region is of length L, then (assuming char *a and ) a[0] … a[L-1] must be valid r and l values at the point of the call.<o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Bill<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<div>
<div>
<div>
<div>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:black">William Gropp<br>
Director and Chief Scientist, NCSA<br>
Thomas M. Siebel Chair in Computer Science<br>
University of Illinois Urbana-Champaign<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
</div>
</div>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
</div>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><o:p> </o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<div>
<p class="MsoNormal">On Jan 2, 2018, at 1:52 PM, Jeff Hammond <<a href="mailto:jeff.science@gmail.com">jeff.science@gmail.com</a>> wrote:<o:p></o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal">If a user passes a (base,size) pair that corresponds to a range of addresses that are not allocated and/or mapped, is that a correct MPI program?<br>
<br>
The only text I can find that implies that buffers passed to MPI_Win_create have to be allocated is the following, assuming that one interprets "existing memory" this way. <br>
<br>
"Each process specifies a window of existing memory that it exposes to RMA accesses by the processes in the group of comm." (MPI 3.1 11.2.1)<br>
<br>
The Fortran-specific text is similarly suggestive, but it only says that a user can pass a simply contiguous array, not that such a thing is required.<br>
<br>
"In Fortran, one can pass the first element of a memory region or a whole array, which must be ‘simply contiguous’"<br>
<br>
Thanks,<br>
<br>
Jeff<br>
<br>
--<br>
Jeff Hammond<br>
<a href="mailto:jeff.science@gmail.com">jeff.science@gmail.com</a><br>
<a href="http://jeffhammond.github.io/">http://jeffhammond.github.io/</a><o:p></o:p></p>
</div>
<p class="MsoNormal">_______________________________________________<br>
mpiwg-rma mailing list<br>
<a href="mailto:mpiwg-rma@lists.mpi-forum.org">mpiwg-rma@lists.mpi-forum.org</a><br>
<a href="https://lists.mpi-forum.org/mailman/listinfo/mpiwg-rma">https://lists.mpi-forum.org/mailman/listinfo/mpiwg-rma</a><o:p></o:p></p>
</div>
</blockquote>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
</div>
</body>
</html>