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<DIV dir=ltr align=left><SPAN class=114555719-31012008><FONT face=Arial
color=#0000ff size=2>Looks ok. Maybe use "specify" instead of
"mention".</FONT></SPAN></DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><TT><SPAN class=114555719-31012008> </SPAN>When an info object
that <SPAN class=114555719-31012008>specifie</SPAN>s a subset of valid
hints<BR><TT> is passed to MPI_FILE_SET_VIEW or MPI_FILE_SET_INFO,
there </TT><BR><TT> will be no effect on previously set or defaulted
hints that </TT><BR><TT> the info does not <SPAN
class=114555719-31012008>specify</SPAN>. </TT></TT></DIV>
<DIV><TT><TT></TT></TT> </DIV>
<DIV><TT><TT><SPAN class=114555719-31012008>Rajeev</SPAN></TT></DIV>
<DIV><BR></TT><BR></DIV>
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<FONT face=Tahoma size=2><B>From:</B> mpi-21-bounces@cs.uiuc.edu
[mailto:mpi-21-bounces@cs.uiuc.edu] <B>On Behalf Of </B>Richard
Treumann<BR><B>Sent:</B> Thursday, January 31, 2008 1:04 PM<BR><B>To:</B>
Mailing list for discussion of MPI 2.1<BR><B>Subject:</B> Re: [mpi-21] Ballot
4 - MPI_File_set_info update or replacement<BR></FONT><BR></DIV>
<DIV></DIV>
<P>Rajeev <BR><BR>I think you just agreed with the interpretation I advocated.
Neither the proposal or rationale made this at all clear to me. How
about?<BR><BR><TT>Proposal:<BR>Add in MPI-2.0 Sect. 9.2.8, File Info, page
218, after line 18 the <BR>following sentences:<BR><BR> When an info
object that mentions a subset of valid hints</TT><BR><TT> is
passed to MPI_FILE_SET_VIEW or MPI_FILE_SET_INFO, there </TT><BR><TT>
will be no effect on previously set or defaulted hints that
</TT><BR><TT> the info does not mention. </TT><BR><TT>
<BR>___________________________________<BR>Rationale for this
clarification:<BR> This text was missing. It was not clear, whether an
info object<BR> in MPI_FILE_SET_VIEW and MPI_FILE_SET_INFO was intended
to </TT><BR><TT> replace only the mentioned hints or was intended
to substitute</TT><BR><TT> a complete new set of hints for the
prior set.<BR>___________________________________</TT><BR><BR>Dick Treumann -
MPI Team/TCEM <BR>IBM Systems & Technology Group<BR>Dept 0lva / MS P963 --
2455 South Road -- Poughkeepsie, NY 12601<BR>Tele (845) 433-7846 Fax (845)
433-8363<BR><BR><BR><TT>mpi-21-bounces@cs.uiuc.edu wrote on 01/31/2008
12:29:41 PM:<BR><BR>> The intent is that if the user calls
MPI_File_set_info (or <BR>> MPI_File_set_view) twice, the 2nd call will
only update (if <BR>> possible) the key-vals passed in the 2nd call; others
are <BR>> unmodified. If the 2nd call passes MPI_INFO_NULL, nothing will
<BR>> change -- it won't nullify previously passed hints.</TT><BR><TT>>
</TT><BR><TT>> Rajeev</TT><BR><TT>> </TT><BR><TT>>
<BR>> From: mpi-21-bounces@cs.uiuc.edu [<A
href="mailto:mpi-21-bounces@cs.uiuc.edu">mailto:mpi-21-bounces@cs.uiuc.edu</A>]
<BR>> On Behalf Of Richard Treumann<BR>> Sent: Thursday, January 31,
2008 9:23 AM<BR>> To: Mailing list for discussion of MPI 2.1<BR>>
Subject: Re: [mpi-21] Ballot 4 - MPI_File_set_info update or
replacement<BR></TT><BR><TT>> I think we have an overall ambiguity about
what the "current set of <BR>> hints" is. This ambiguity is evident in the
question about what <BR>> MPI_FILE_INFO_GET returns and in this discussion
too. If an <BR>> implementation supports 5 file hints then it must select a
value for<BR>> each of these hints an MPI_FILE_OPEN. If there is an
MPI_Info that <BR>> stipulates 2 of the hints then how many hints are in
the "current <BR>> set of hints"? 2 or 5? I would say there are 5 and I
think it makes <BR>> sense for MPI_FILE_GET_INFO to return all 5
(key,value) pairs.<BR>> <BR>> Two more specific points -<BR>>
<BR>> 1) I would expect that if at MPI_FILE_OPEN the implementation is
<BR>> given non-default hints ("A","yes") and ("B","no") and then at
<BR>> MPI_FILE_INFO_SET is given ("B","yes") the net effect is that hint
<BR>> "A" remains as set and hint "B" is altered (if possible). If there
<BR>> is a hint "C" which has never been mentioned it will have received
a<BR>> default value at MPI_FILE_OPEN and the MPI_FILE_INFO_SET which does
<BR>> not mention "C" will leave that default unchanged.<BR>> <BR>>
Is the "clarification" saying hint "A" must return to default when <BR>>
MPI_FILE_INFO_SET fails to mention it? If that is the intent then I <BR>>
need to be convinced. If we decide this is to be blessed then we <BR>>
probably need to say that any use of MPI_FILE_SET_INFO must first <BR>>
call MPI_FILE_GET_INFO, tweek the INFO it gets back from <BR>>
MPI_FILE_GET_INFO and pass that to MPI_FILE_SET_INFO to avoid <BR>>
unexpected changes to the set of hints that is "in effect".<BR>> <BR>>
2) Since a hint is a hint, not a command, it can be rejected. It is <BR>>
possible that some hint can be honored at MPI_FILE_OPEN but once it <BR>>
has been honored, cannot be altered at reasonable cost. <BR>> <BR>> For
example, maybe somebody's MPI_FILE_OPEN could accept a hint <BR>>
("buffer_size", "dynamic-64MB") meaning "start with a 64MB buffer <BR>> but
be prepared to accept changes to buffer size". If the user has <BR>> set
hint ("buffer_size", "64MB") at FILE_OPEN, the implelentation <BR>> would
omit whatever synchs are needed to preserve the ability to <BR>> change on
the fly. Passing ("buffer_size", "dynamic-16MB") to <BR>> MPI_FILE_SET_INFO
could be honored if the user had chosen "dynamic" <BR>> at FILE_OPEN but
would need to be ignored if he had not.<BR>> <BR>> For most
implementations, a hint like "buffer_size" could not be <BR>> honored at
all after the first file read or write had been done.<BR>> <BR>> Dick
Treumann - MPI Team/TCEM <BR>> IBM Systems & Technology Group<BR>>
Dept 0lva / MS P963 -- 2455 South Road -- Poughkeepsie, NY 12601<BR>> Tele
(845) 433-7846 Fax (845) 433-8363<BR>> <BR>> <BR>>
mpi-21-bounces@cs.uiuc.edu wrote on 01/31/2008 08:24:51 AM:<BR>> <BR>>
> This is a proposal for MPI 2.1, Ballot 4.<BR>> > <BR>> > I'm
asking especially the implementors to check, whether<BR>> > this
interpretation is implemented in their MPI implementations,<BR>> > or
does not contradict to the existing implementation.<BR>> > <BR>> >
This is a follow up to:<BR>> > MPI_File_set_info<BR>> >
in <A
href="http://www.cs.uiuc.edu/homes/wgropp/projects/parallel/MPI/mpi-">http://www.cs.uiuc.edu/homes/wgropp/projects/parallel/MPI/mpi-</A><BR>>
> errata/index.html<BR>> > with mail discussion not yet
existing<BR>> > ___________________________________<BR>> >
<BR>> > Proposal:<BR>> > Add in MPI-2.0 Sect. 9.2.8, File Info,
page 218, after line 18 the <BR>> > following sentences:<BR>> >
<BR>> > With MPI_FILE_SET_VIEW and MPI_FILE_SET_INFO the current
setting<BR>> > of all hints used by the system to this open file
is updated by <BR>> > the (key,value) pairs in the info
argument.<BR>> > ___________________________________<BR>> >
Rationale for this clarification:<BR>> > This text was missing.
It was not clear, whether a info handles<BR>> > in
MPI_FILE_SET_VIEW and MPI_FILE_SET_INFO are updating or replacing<BR>> >
the current set of used hints. <BR>> > The developers from
ROMIO decided to update the current set of used hints.<BR>> >
Therefore, this behavior should be the expected behavior of a majority<BR>>
> of users.<BR>> > ___________________________________<BR>>
> <BR>> > Best regards<BR>> > Rolf<BR>> > <BR>> >
<BR>> > <BR>> > <BR>> > Dr. Rolf Rabenseifner . . . . . . .
. . .. email rabenseifner@hlrs.de<BR>> > High Performance Computing
Center (HLRS) . phone ++49(0)711/685-65530<BR>> > University of
Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832<BR>> > Head of
Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner<BR>> >
Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30)<BR>>
> _______________________________________________<BR>> > mpi-21
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