recommend Toyota Yaris

Just bought a 2007 Toyato Yaris Hatchback. It is small, but ridiculously has large room even for my mountain bike. It is so efficient, 40MPG for me including local and highway (half and half).

resolve MPI deadlocking

Deadlock is a problem with blocked communication.

Example 1: always deadlocking

if (rank == 0) then
   call MPI_Recv(..., 1, tag, MPI_COMM_WORLD, status, ierr)
   call MPI_Send(..., 1, tag, MPI_COMM_WORLD, ierr)
elseif (rank == 1) then
   call MPI_Recv(..., 0, tag, MPI_COMM_WORLD, status, ierr)
   call MPI_Send(..., 0, tag, MPI_COMM_WORLD, ierr)
endif

Example 2: sometimes deadlocking: MPI is using internal buffers (the “message envelope”) to cache messages. A blocked comm pattern may work for some values of count, and then fail as count is increased.

if (rank == 0) then
   call MPI_Send(..., 1, tag, MPI_COMM_WORLD, ierr)
   call MPI_Recv(..., 1, tag, MPI_COMM_WORLD, status, ierr)
elseif (rank == 1) then
   call MPI_Send(..., 0, tag, MPI_COMM_WORLD, ierr)
   call MPI_Recv(..., 0, tag, MPI_COMM_WORLD, status, ierr)
endif

A couple of ways to fix this problem.
Method 1: reverse the order of one of the send/receive pairs

if (rank == 0) then
   call MPI_Send(..., 1, tag, MPI_COMM_WORLD, ierr)
   call MPI_Recv(..., 1, tag, MPI_COMM_WORLD, status, ierr)
elseif (rank == 1) then
   call MPI_Recv(..., 0, tag, MPI_COMM_WORLD, status, ierr)
   call MPI_Send(..., 0, tag, MPI_COMM_WORLD, ierr)
endif

Method 2: using unblocked communication

if (rank == 0) then
   call MPI_Isend(..., 1, tag, MPI_COMM_WORLD, req, ierr)
   call MPI_Recv(..., 1, tag, MPI_COMM_WORLD, status, ierr)
   call MPI_Wait(req, status)
elseif (rank == 1) then
   call MPI_Recv(..., 0, tag, MPI_COMM_WORLD, status, ierr)
   call MPI_Send(..., 0, tag, MPI_COMM_WORLD, ierr)
endif

Remodeling at SAFL

Recently, SAFL is remodeling the entrance.
Taken at 10/13/2009 11:16 by Fujifilm FinePix805; Shutter 1/204seconds; F2.83; ISO100; no flash.

front and backyard of my current house

time: 10/18/2009, 17:09
camera: Fujifilm FinePix805
shutter: 1/405 seconds
aperture: F2.83
iso200; no flash

10/10/2009 night MPLS downtown from SAFL

Looking at Minneapolis downtown from St. Anthony Falls Lab.


Time: 10/10/2009, 21:17. Fujifilm FinePix 805 landscape-night mode; Shutter 2seconds; Aperture F2.83; ISO 200, no Flash.