Hi, Rajeev<br><div style="margin-left: 40px;">Is process scheduling within a single core done by Operating system or by MPICH itself?<br><br clear="all"></div>Regards,<br>Waruna Ranasinghe<br><br>
<br><br><div class="gmail_quote">2008/11/30 Rajeev Thakur <span dir="ltr"><<a href="mailto:thakur@mcs.anl.gov">thakur@mcs.anl.gov</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div dir="ltr" align="left"><span><font size="2" color="#0000ff" face="Arial">Then you can expect a slowdown if you run 6 processes on 4
cores.</font></span></div><br>
<blockquote style="border-left: 2px solid rgb(0, 0, 255); padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div dir="ltr" align="left" lang="en-us">
<hr>
<font size="2" face="Tahoma"><div class="Ih2E3d"><b>From:</b> <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>
[mailto:<a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] <b>On Behalf Of </b>Waruna
Ranasinghe<br></div><b>Sent:</b> Saturday, November 29, 2008 11:32 PM<div><div></div><div class="Wj3C7c"><br><b>To:</b>
<a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br><b>Subject:</b> Re: [mpich-discuss] Clarification
needed on runningprocessesonMPICH2<br></div></div></font><br></div><div><div></div><div class="Wj3C7c">
<div></div>no only 4<br><br>
<div class="gmail_quote">2008/11/30 Rajeev Thakur <span dir="ltr"><<a href="mailto:thakur@mcs.anl.gov" target="_blank">thakur@mcs.anl.gov</a>></span><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div dir="ltr" align="left"><span><font size="2" color="#0000ff" face="Arial">But you
don't have 6 cores, do you?</font></span></div><br>
<blockquote style="border-left: 2px solid rgb(0, 0, 255); padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div dir="ltr" align="left" lang="en-us">
<hr>
<font size="2" face="Tahoma">
<div><b>From:</b> <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a> [mailto:<a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] <b>On Behalf Of
</b>Waruna Ranasinghe<br></div><b>Sent:</b> Saturday, November 29, 2008
11:03 PM
<div>
<div></div>
<div><br><b>To:</b> <a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br><b>Subject:</b> Re:
[mpich-discuss] Clarification needed on
runningprocessesonMPICH2<br></div></div></font><br></div>
<div>
<div></div>
<div>
<div></div>Yes, I'm sorry if you were miss led by my wordings.<br>I meant
running two instances.<br><br>
<div class="gmail_quote">2008/11/30 Rajeev Thakur <span dir="ltr"><<a href="mailto:thakur@mcs.anl.gov" target="_blank">thakur@mcs.anl.gov</a>></span><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div dir="ltr" align="left"><span><font size="2" color="#0000ff" face="Arial">If
you run two instances of mpiexec -n 3 tst, you are running a total of 6
processes, not 2 or 3. </font></span></div>
<div dir="ltr" align="left"><span><font size="2" color="#0000ff" face="Arial"></font></span> </div>
<div dir="ltr" align="left"><span><font size="2" color="#0000ff" face="Arial">Rajeev</font></span></div><br>
<blockquote style="border-left: 2px solid rgb(0, 0, 255); padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div dir="ltr" align="left" lang="en-us">
<hr>
<font size="2" face="Tahoma">
<div><b>From:</b> <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a> [mailto:<a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] <b>On Behalf Of
</b>Waruna Ranasinghe<br></div><b>Sent:</b> Saturday, November 29,
2008 5:38 AM
<div>
<div></div>
<div><br><b>To:</b> <a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br><b>Subject:</b> Re:
[mpich-discuss] Clarification needed on
runningprocessesonMPICH2<br></div></div></font><br></div>
<div>
<div></div>
<div>
<div></div>>What do you mean by "one process" when it is clearly
3<br>>processes are running ? When you say 2 processes of
tst,<br>>do you mean you launched two instances of<br>>"mpiexec
-n 3 ./tst" simultaneously.<br><br>Yes, I meant of launching two
instances of "mpiexec -n 3 ./tst" simultaneously.<br><br>I could not
reach the MPICH cluster until monday, so that I'll send the modified
programme on Monday.<br><br>Thank You,<br>Waruna<br><br>
<div class="gmail_quote">2008/11/29 Anthony Chan <span dir="ltr"><<a href="mailto:chan@mcs.anl.gov" target="_blank">chan@mcs.anl.gov</a>></span><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">>From
your Readme file:<br><br>> mpiexec -n 3
<path><br>><br>> output:<br>> when only one process
runs<br>><br>> 0:Total: 499999999500000000 : Time:
9.272023<br>> 2:Total: 499999999500000000 : Time:
10.722239<br>> 1:Total: 499999999500000000 : Time:
11.324907<br>><br>> When two processes of 'tst' runs in the
same time<br>><br>> 0:Total: 499999999500000000 : Time:
9.538206<br>> 2:Total: 499999999500000000 : Time:
16.045104<br>> 1:Total: 499999999500000000 : Time:
22.400754<br><br>What do you mean by "one process" when it is
clearly 3<br>processes are running ? When you say 2 processes
of tst,<br>do you mean you launched two instances of<br>"mpiexec -n
3 ./tst" simultaneously.<br><br>Could you add the following lines to
your tst.cpp<br><br> char host_name[
MPI_MAX_PROCESSOR_NAME ];<br> int
namelen;<br>
MPI_Get_processor_name( host_name, &namelen
);<br> printf("rank %d running on
%s\n", rank, host_name);<br><br>before first fflush(stdout) to show
the location of each process.<br>Rerun your experiments and let us
know the result.<br><br>Also, you can use MPI_Wtime() instead of
Duration.cpp that may<br>simplify your test program.<br>
<div>
<div></div>
<div><br>A.Chan<br><br>----- "Waruna Ranasinghe" <<a href="mailto:warunapww@gmail.com" target="_blank">warunapww@gmail.com</a>> wrote:<br><br>> Hi
Rajeev,<br>> Here's test programme. It's just for testing. The
results I got, are<br>> in the<br>> read me file in the
attachment<br>><br>> Thank You<br>> Waruna<br>><br>>
2008/11/27 Rajeev Thakur <<a href="mailto:thakur@mcs.anl.gov" target="_blank">thakur@mcs.anl.gov</a>><br>><br>> >
In that case, what kind of program are you running? Can you
send us<br>> a<br>> > small test program.<br>>
><br>> > Rajeev<br>> ><br>> >
------------------------------<br>> > *From:* <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a> [mailto:<br>>
> <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] *On Behalf Of
*Waruna Ranasinghe<br>> > *Sent:* Wednesday, November 26, 2008
9:05 PM<br>> ><br>> > *To:* <a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br>> > *Subject:*
Re: [mpich-discuss] Clarification needed on<br>> >
runningprocessesonMPICH2<br>> ><br>> > Hi
Rajeev,<br>> > There's no doubt that process runs on all 3
machines.<br>> > I have tried cpi example and it prints the
hostnames of 3 machines<br>> ><br>> > mpiexec -l -n 3
<path to process><br>> > (the same path is available in
all 3 machines)<br>> ><br>> > Thank you<br>> >
Waruna<br>> ><br>> ><br>> > 2008/11/26 Rajeev
Thakur <<a href="mailto:thakur@mcs.anl.gov" target="_blank">thakur@mcs.anl.gov</a>><br>> ><br>>
>> Make sure the processes are actually running on the 3
machines.<br>> Try the<br>> >> cpi example in the
examples directory. It prints out the hostname.<br>> How
are<br>> >> you running the job?<br>> >><br>>
>> Rajeev<br>> >><br>> >>
------------------------------<br>> >> *From:*
<a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a> [mailto:<br>>
>> <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] *On Behalf Of
*Waruna<br>> Ranasinghe<br>> >> *Sent:* Wednesday,
November 26, 2008 11:07 AM<br>> >><br>> >> *To:*
<a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br>> >>
*Subject:* Re: [mpich-discuss] Clarification needed on
running<br>> >> processesonMPICH2<br>> >><br>>
>> Fedora 8 - MPICH2 one machine with core-2-duo -
master<br>> >> two machines with one core<br>> >>
all together 3 nodes<br>> >><br>> >> 2008/11/26
Rajeev Thakur <<a href="mailto:thakur@mcs.anl.gov" target="_blank">thakur@mcs.anl.gov</a>><br>> >><br>>
>>> What kind of environment are you running on (how
many machines,<br>> how<br>> >>> many cores
each)?<br>> >>><br>> >>> Rajeev<br>>
>>><br>> >>>
------------------------------<br>> >>>
*From:* <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a> [mailto:<br>>
>>> <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] *On Behalf Of
*Waruna<br>> Ranasinghe<br>> >>> *Sent:* Wednesday,
November 26, 2008 2:15 AM<br>> >>> *To:* <a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br>> >>>
*Subject:* Re: [mpich-discuss] Clarification needed on
running<br>> processes<br>> >>> onMPICH2<br>>
>>><br>> >>> Hi Anthony,<br>>
>>> I'm sorry, in this case I have to disagree with
you.<br>> >>> Because it is not max(t1,t2) but t1+t2
(this is the real result I<br>> got)<br>> >>> I use
fflush(stdout) also<br>> >>><br>> >>> What I
think is that, Cluster runs two programmes alternatively.<br>>
>>> i.e. Process A runs for a while (say t3 seconds) then
process B<br>> for<br>> >>> sometime and so
on.<br>> >>> Therefore, ultimately both the processes
will run for t1+t2<br>> >>><br>> >>>
Cluster: MPICH2<br>> >>> Fedora 8<br>>
>>><br>> >>> 2008/11/26 Anthony Chan <<a href="mailto:chan@mcs.anl.gov" target="_blank">chan@mcs.anl.gov</a>><br>> >>><br>>
>>>><br>> >>>> If process A and B are
launched by mpiexec, the time taken<br>> >>>> by
mpiexec should be max(t1,t2) not t1 + t2. As Rajeev said,<br>>
>>>> calling fflush(stdout) after each printf() is the
fastest way<br>> >>>> to get each process's stdout
printed to your console.<br>> >>>><br>>
>>>> A.Chan<br>> >>>> ----- "Waruna
Ranasinghe" <<a href="mailto:warunapww@gmail.com" target="_blank">warunapww@gmail.com</a>> wrote:<br>>
>>>><br>> >>>> > Hi Rajeev,<br>>
>>>> > Actually this is not what I'm talking
about.<br>> >>>> > Say there are processes A and
B<br>> >>>> > Process A utilize 100% of the cpu
while it runs. The answer<br>> will<br>> >>>> >
appear in<br>> >>>> > t1 seconds<br>>
>>>> > Process B also utilize 100% of the cpu while
it runs. The<br>> answer will<br>> >>>> >
appear<br>> >>>> > in t2 seconds<br>>
>>>> ><br>> >>>> > When I run both
the process A and B at the same time, The both<br>>
answers<br>> >>>> > will<br>> >>>>
> appear in t1 + t2 seconds. where as I want to get the
Process<br>> A's<br>> >>>> > answer<br>>
>>>> > first. (Here Process A is submitted before
Process B)<br>> >>>> ><br>> >>>>
> Is there anything that I can do to make this happen.<br>>
>>>> ><br>> >>>> > Thank
You,<br>> >>>> > Waruna<br>> >>>>
><br>> >>>> > 2008/11/26 Rajeev Thakur <<a href="mailto:thakur@mcs.anl.gov" target="_blank">thakur@mcs.anl.gov</a>><br>> >>>>
><br>> >>>> > > If you are refering to
the output of "printf", you can try<br>> adding<br>>
>>>> > an<br>> >>>> > >
fflush(stdout) after the printf. You don't have much control<br>>
over<br>> >>>> > the order<br>>
>>>> > > in which it is printed from different
processes.<br>> >>>> > ><br>>
>>>> > > Rajeev<br>> >>>> >
><br>> >>>> > >
------------------------------<br>> >>>> >
> *From:* <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a> [mailto:<br>>
>>>> > > <a href="mailto:mpich-discuss-bounces@mcs.anl.gov" target="_blank">mpich-discuss-bounces@mcs.anl.gov</a>] *On Behalf Of
*Waruna<br>> Ranasinghe<br>> >>>> > >
*Sent:* Tuesday, November 25, 2008 1:35 AM<br>> >>>>
> > *To:* <a href="mailto:mpich-discuss@mcs.anl.gov" target="_blank">mpich-discuss@mcs.anl.gov</a><br>> >>>>
> > *Subject:* [mpich-discuss] Clarification needed on
running<br>> processes<br>> >>>> > on<br>>
>>>> > > MPICH2<br>> >>>> >
><br>> >>>> > > Hi all,<br>>
>>>> > > I submitted 3 processes at the same time
using mpiexec. the<br>> results<br>> >>>> > of
each<br>> >>>> > > process appears only after
all the processes have finished.<br>> (I guess<br>>
>>>> > that<br>> >>>> > > the
way mpich schedule it).<br>> >>>> > > What if I
want to get the result of the process, which was<br>>
submitted<br>> >>>> > first,<br>>
>>>> > > first. (like first in first out).<br>>
>>>> > ><br>> >>>> > > I use
MPICH2 cluster in Fedora 8 (with mpd)<br>> >>>> >
><br>> >>>> > > Thank you.<br>>
>>>> > > Waruna Ranasinghe<br>>
>>>> > ><br>> >>>> >
><br>> >>>><br>> >>><br>>
>>><br>> >><br>>
><br></div></div></blockquote></div><br></div></div></blockquote></div></blockquote></div><br></div></div></blockquote></div></blockquote></div><br></div></div></blockquote></div>
</blockquote></div><br>