Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |  

This web mail archive is frozen.

This page is part of a frozen web archive of this mailing list.

You can still navigate around this archive, but know that no new mails have been added to it since July of 2016.

Click here to be taken to the new web archives of this list; it includes all the mails that are in this frozen archive plus all new mails that have been sent to the list since it was migrated to the new archives.

Subject: [OMPI devel] Some questions about checkpoint/restart (5)
From: Takayuki Seki (seki_at_[hidden])
Date: 2010-03-18 05:06:43


5th question is as follows:

(5) Receving with MPI_ANY_SOURCE,MPI_ANY_TAG.

This problem might have already been announced by the Open MPI Trac with "Ticket #1769".
This problem will occur with usual MPI program.

Framework : crcp
Component : bkmrk
The source file : ompi/mca/crcp/bkmrk/crcp_bkmrk_pml.c
The function name : do_recv_msg_detail_check_drain,traffic_message_find

Here's the code that causes the problem:

#define BLOCKNUM 1048576
#define SLPTIM 60

  if (rank == 0) {
    MPI_Send(wbuf,BLOCKNUM,MPI_INT,1,100,MPI_COMM_WORLD);
    MPI_Send(wbuf,BLOCKNUM,MPI_INT,1,100,MPI_COMM_WORLD);
    MPI_Send(wbuf,BLOCKNUM,MPI_INT,1,100,MPI_COMM_WORLD);
    MPI_Isend(wbuf,BLOCKNUM,MPI_INT,1,200,MPI_COMM_WORLD,&sreq[5]);
    printf(" rank=%d sleep start \n",rank); fflush(stdout);
    sleep(SLPTIM); /** take checkpoint at this point **/
    printf(" rank=%d sleep end \n",rank); fflush(stdout);
    MPI_Wait(&sreq[5],&ssts[5]);
  }
  else { /* rank 1 */
    MPI_Recv(rbuf,BLOCKNUM,MPI_INT,0,100,MPI_COMM_WORLD,&rsts[2]);
    MPI_Irecv(rbuf,BLOCKNUM,MPI_INT,MPI_ANY_SOURCE,MPI_ANY_TAG,MPI_COMM_WORLD,&rreq[3]); MPI_Wait(&rreq[3],&rsts[3]);
    MPI_Irecv(rbuf,BLOCKNUM,MPI_INT,0,100,MPI_COMM_WORLD,&rreq[4]); MPI_Wait(&rreq[4],&rsts[4]);
    printf(" rank=%d sleep start \n",rank); fflush(stdout);
    sleep(SLPTIM); /** take checkpoint at this point **/
    printf(" rank=%d sleep end \n",rank); fflush(stdout);
    MPI_Recv(rbuf,BLOCKNUM,MPI_INT,0,200,MPI_COMM_WORLD,&rsts[5]);
  }

* Take checkpoint while Rank 0 and Rank 1 are performing sleep function

* There are two messages which are considered to be an same condition by MPI_ANY_SOURCE,MPI_ANY_TAG in irecv_list.
  It is as follows:

[IRECV=1e44a00 comm_id=6019e0/0/1 msgid=6 count=1048576 tag=100 rank=0 proc_name=-833290239/0 matched=0 done=1 active=0 drain=0 ] [c=0 r=1]
[IRECV=1e44b80 comm_id=6019e0/0/1 msgid=5 count=1048576 tag=-1 rank=-1 proc_name=-833290239/0 matched=0 done=1 active=0 drain=0 ] [c=0 r=1]

* However, do_recv_msg_detail_check_drain function obtains either message information via traffic_message_find.

* Therefore, the other message information can not be obtained.

-bash-3.2$ cat t_mpi_question-5.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "mpi.h"

#define BLOCKNUM 1048576
#define SLPTIM 60

int main(int ac,char **av)
{
  int i;
  int rank,size;
  int *wbuf;
  int *rbuf;
  MPI_Status rsts[4],ssts[4];
  MPI_Request rreq[4],sreq[4];
  int bufsize,count;

  MPI_Init(&ac,&av);

  MPI_Comm_rank(MPI_COMM_WORLD,&rank);
  MPI_Comm_size(MPI_COMM_WORLD,&size);
  printf(" rank=%d size=%d \n",rank,size); fflush(stdout);
  if (size != 2) { MPI_Abort(MPI_COMM_WORLD,-1); }

  rbuf = (int *)malloc(BLOCKNUM * sizeof(int));
  wbuf = (int *)malloc(BLOCKNUM * sizeof(int));
  if ((rbuf == NULL)||(wbuf == NULL)) { MPI_Abort(MPI_COMM_WORLD,-1); }

  printf(" rank=%d pass-1 \n",rank); fflush(stdout);

  MPI_Barrier(MPI_COMM_WORLD);

  if (rank == 0) {
    for (i=0;i<BLOCKNUM;i++) { wbuf[i] = (100+i); }
    MPI_Send(wbuf,BLOCKNUM,MPI_INT,1,100,MPI_COMM_WORLD);

    for (i=0;i<BLOCKNUM;i++) { wbuf[i] = (200+i); }
    MPI_Send(wbuf,BLOCKNUM,MPI_INT,1,100,MPI_COMM_WORLD);

    for (i=0;i<BLOCKNUM;i++) { wbuf[i] = (300+i); }
    MPI_Send(wbuf,BLOCKNUM,MPI_INT,1,100,MPI_COMM_WORLD);

    for (i=0;i<BLOCKNUM;i++) { wbuf[i] = (400+i); }
    MPI_Isend(wbuf,BLOCKNUM,MPI_INT,1,200,MPI_COMM_WORLD,&sreq[0]);

    printf(" rank=%d sleep start \n",rank); fflush(stdout);
    sleep(SLPTIM);
    printf(" rank=%d sleep end \n",rank); fflush(stdout);

    MPI_Wait(&sreq[0],&ssts[0]);
  }
  else {
    for (i=0;i<BLOCKNUM;i++) { rbuf[i] = 0; }
    MPI_Recv(rbuf,BLOCKNUM,MPI_INT,0,100,MPI_COMM_WORLD,&rsts[0]);
    for (i=0;i<BLOCKNUM;i++) { if(rbuf[i] != (100+i)) { MPI_Abort(MPI_COMM_WORLD,1); } }

    for (i=0;i<BLOCKNUM;i++) { rbuf[i] = 0; }
    MPI_Irecv(rbuf,BLOCKNUM,MPI_INT,MPI_ANY_SOURCE,MPI_ANY_TAG,MPI_COMM_WORLD,&rreq[1]); MPI_Wait(&rreq[1],&rsts[0]);
    for (i=0;i<BLOCKNUM;i++) { if(rbuf[i] != (200+i)) { MPI_Abort(MPI_COMM_WORLD,1); } }

    for (i=0;i<BLOCKNUM;i++) { rbuf[i] = 0; }
    MPI_Irecv(rbuf,BLOCKNUM,MPI_INT,0,100,MPI_COMM_WORLD,&rreq[2]); MPI_Wait(&rreq[2],&rsts[2]);
    for (i=0;i<BLOCKNUM;i++) { if(rbuf[i] != (300+i)) { MPI_Abort(MPI_COMM_WORLD,1); } }

    printf(" rank=%d sleep start \n",rank); fflush(stdout);
    sleep(SLPTIM);
    printf(" rank=%d sleep end \n",rank); fflush(stdout);

    for (i=0;i<BLOCKNUM;i++) { rbuf[i] = 0; }
    MPI_Recv(rbuf,BLOCKNUM,MPI_INT,0,200,MPI_COMM_WORLD,&rsts[3]);
    for (i=0;i<BLOCKNUM;i++) { if(rbuf[i] != (400+i)) { MPI_Abort(MPI_COMM_WORLD,1); } }
  }

  MPI_Barrier(MPI_COMM_WORLD);
  free(rbuf);
  free(wbuf);
  MPI_Finalize();
  if (rank == 0) {
    printf(" rank=%d program end \n",rank); fflush(stdout); fflush(stderr);
  }
  return(0);
}