Commit 7763022d authored by buntinas's avatar buntinas
Browse files

added warning in README and configure regarding using processor cycle counters...

added warning in README and configure regarding using processor cycle counters for --enable-timer-type.  Also added text regarding shared MX GM and Elan libraries to README.
parent b4709f2b
......@@ -486,6 +486,17 @@ TCP.
(Note : This module is still in *experimental* state. It has not
been thoroughly tested and performance issues remain.)
Note that if the GM, MX or Elan libraries are shared libraries, they
need to be in the shared library search path. This can be done by
adding the path to /etc/ld.so.conf, or by setting the
LD_LIBRARY_PATH variable in your .bashrc (or .tcshrc) file. It's
also possible to set the shared library search path in the binary.
If you're using gcc, you can do this by adding
LD_LIBRARY_PATH=/path/to/lib
and
MPI_LDFLAGS="-Wl,-rpath -Wl,/path/to/lib"
as arguments to configure.
Using the --enable-fast configure option significantly improves
intra-node performance.
......@@ -691,6 +702,24 @@ Compilation options for development:
More information on the logging options, capabilities
and usage can be found in doc/logging/logging.pdf.
--enable-timer-type=name - Select the timer to use for MPI_Wtime
and internal timestamps. name may be one of:
gethrtime - Solaris timer (Solaris systems
only)
clock_gettime - Posix timer (where available)
gettimeofday - Most Unix systems
linux86_cycle - Linux x86; returns cycle
counts, not time in seconds*
linuxalpha_cycle - Like linux86_cycle, but for
Linux Alpha*
gcc_ia64_cycle - IPF ar.itc timer*
device - The timer is provided by the device
*Note that the cycle timers are intended to be used by
MPICH2 developers for internal low-level timing.
Normal users should not use these as they are not
guaranteed to be accurate in certain situations.
Status of MPI-2 Features in MPICH2
==================================
......
......@@ -4603,12 +4603,16 @@ dnl We also allow --enable-timer-type=name to select a timer type
AC_ARG_ENABLE(timer-type,[--enable-timer-type=name - Select the timer to use
for MPI_Wtime and internal timestamps. name may be one of
gethrtime - Solaris timer (Solaris systems only)
clock_gettime - Posix timer (where available)
clock_gettime - Posix timer (where available)
gettimeofday - Most Unix systems
linux86_cycle - Linux x86; returns cycle counts, not time in seconds
linuxalpha_cycle - Like linux86_cycle, but for Linux Alpha
gcc_ia64_cycle - IPF ar.itc timer
linux86_cycle - Linux x86; returns cycle counts, not time in seconds*
linuxalpha_cycle - Like linux86_cycle, but for Linux Alpha*
gcc_ia64_cycle - IPF ar.itc timer*
device - The timer is provided by the device
*Note that the cycle timers are intended to be used by MPICH2
developers for internal low-level timing. Normal users should
not use these as they are not guaranteed to be accurate in
certain situations.
],timer_type=$enable_timer_type)
if test -z "$timer_type" ; then
......
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