[mpich-discuss] mpich2 and stdin longer than 1024 lines

[Bryan Putnam]

Hi All,

We've noticed that when using mpich2-1.0.7, the mpi application will hang 
when using a stdin that is longer than 1024 lines.  You can easily 
reproduce this using the famous "pi" program set up to read from stdin. 
For example using 2 processors on each of 2 nodes:

perl -e 'print "100\n" x 1023; print "0\n"' > inp
mpdboot -n 2 -f $PBS_NODEFILE
mpirun -np 4 ./pi < inp

works fine, while

perl -e 'print "100\n" x 1024; print "0\n"' > inp
mpdboot -n -f $PBS_NODEFILE
mpirun -np 4 ./pi < inp

hangs.

Note that a workaround is to do

mpirun -np 4 "cat inp | pi"

Any help on what to modify in the mpich2 scripts to fix this would be 
appreciated.

Thanks!
Bryan


--
Bryan Putnam
Rosen Center for Advanced Computing, Purdue University
Young Hall (Rm. 519)
302 Wood Street
West Lafayette, IN 47907-2108
Ph 765-496-8225 Fax 765-494-0566
bfp at purdue.edu
http://www.rcac.purdue.edu