[mvapich-discuss] Listing of "hidden" MV2 environment variables?

[Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC]]

All,

In my recent attempts to diagnose and workaround this issue [1]:

> http://mailman.cse.ohio-state.edu/pipermail/mvapich-discuss/2015-January/005296.html

I've been twiddling various MV2_ environmental knobs by looking at the 
output of MV2_SHOW_ENV_INFO=2 and I eventually realized that that 
setting does not show all environment variables.

For example, it turns out that, at least for one case (the above 336 
process one), MV2_USE_BLOCKING=1 seems to workaround the issue.

However, in a "stock option" run of MVAPICH2 2.1rc1--where 
MV2_USE_BLOCKING=0 is the default setting--MV2_USE_BLOCKING does not 
show up in the listing of MV2_SHOW_ENV_INFO=2. It's only shown if it is 
toggled.

So, I was wondering, does anyone have a listing of what knobs are 
turnable in MVAPICH2 (say in the User's Guide) but aren't included in 
MV2_SHOW_ENV_INFO=2?

Or, perhaps, is there a higher value of MV2_SHOW_ENV_INFO that shows 
them (a la I_MPI_DEBUG in Intel MPI)? I tried 3 but nothing really 
happened save the =1 prints.

(Note: Some further testing seems to show that it's actually 
MV2_USE_SHARED_MEM=0 set by MV2_USE_BLOCKING=1 that's helping. More to 
test!)

Matt

[1] Update: looks like changing MV2_SMP_NUM_SEND_BUFFER and 
MV2_EAGERSIZE_1SC[2] to their Westmere/DDR values do not always solve 
the problem. On 336 cores, it seems to be more reliably halting at all 
times.

[2] Does anyone know what MV2_EAGERSIZE_1SC does? It does not seem to 
exist in the User's Guide.

-- 
Matt Thompson          SSAI, Sr Software Test Engr
NASA GSFC, Global Modeling and Assimilation Office
Code 610.1, 8800 Greenbelt Rd, Greenbelt, MD 20771
Phone: 301-614-6712              Fax: 301-614-6246