Features of recent releases

Version 1.2.6 of mpich is primarily a bug fix and increased portability release, particularly for Linux-based clusters.

New and improved in 1.2.6:

Improved build for Mac OSX, including use of the IBM compilers

Many small fixes

Additional improvements to the collective algorithms

Updated Globus2 device for Globus 2.2 or later

Improved SLOG and Jumpshot

New collective algorithms

Better handling of startup in the ch_p4 device.

Added support for the POSIX sched_yield call. This significantly increases the performance of the ch_shmem device and ch_p4 device when -comm=shared is chosen, when there are more total processes (including operating system and other user processes) than processors on a node. This is now the default where available. However, when there are fewer processes than processors, lower latencies can be achieved by configuring with --disable-yield.

The option --with-common-prefix=dir can be used to set the directory path for installing tools such as upshot and jumpshot that are independent of the MPICH device. For example,

 configure --with-device=ch_p4 --prefix=/usr/local/mpich-1.2.4/ch_p4 \ 
     --with-common-prefix=/usr/local/mpich-1.2.4 
 make  
 make install 
 configure --with-device=ch_p4mpd  --prefix=/usr/local/mpich-1.2.4/ch-p4mpd \ 
     --with-common-prefix=/usr/local/mpich-1.2.4 

Added CYGWIN_NT to known architectures.

Added more support for the MPI-2 feature MPI_STATUS_NULL.

Fixed several bugs in the flow control code that could cause programs to hang.

Many improvements to the MPICH-NT version.

A bug in the autoconf macro AC_CHECK_HEADER has been fixed; this caused configure to conclude that header files were not available even though they were.

Fixes for NETBSD (usc code in ch_p4)

Reorganized manuals, arranged by device and including a frequently asked questions section.

Further improvements to the ch_p4mpd device.

Improvements to the SMP support in the ch_p4 device, thanks to Pete Wykcoff.

Support for IA64 systems running Linux and for Mac OS X.

Support for version 2 of Globus in the globus2 device.

Many bug fixes and code improvements. See www.mcs.anl.gov/mpi/mpich1/r1_2_3changes.html for a complete list of changes.

A greatly improved ch_p4mpd device.

Improved support for assorted Fortran 77 and Fortran 90 compilers, including compile-time evaluation of Fortran constants used in the mpich implementation.

An improved globus2 device, providing better performance.

A new bproc mode for the ch_p4 device supports Scyld Beowulfs.

Many TCP performance improvements for the ch_p4 and ch_p4mpd devices, as well as

Many bug fixes and code improvements. See www.mcs.anl.gov/mpi/mpich1/r1_2_2changes.html for a complete list of changes.