Question

我正在尝试调整following example program以在我的实验中用作粗粒度的平行基准。

我在代码中添加了以下行：

      START_TIME = MPI_WTIME() * <- added this
      CALL PDGESV( N, NRHS, MEM( IPA ), 1, 1, DESCA, MEM( IPPIV ),
     $             MEM( IPB ), 1, 1, DESCB, INFO )
*
      IF( MYROW.EQ.0 .AND. MYCOL.EQ.0 ) THEN
         WRITE( NOUT, FMT = * )
         WRITE( NOUT, FMT = * ) 'INFO code returned by PDGESV = ', INFO
         WRITE( NOUT, FMT = * )
         WRITE( NOUT, FMT = * ) 'Matrix X = A^{-1} * B'
         WRITE( NOUT, FMT = * )
      END IF
      CALL PDLAPRNT( N, NRHS, MEM( IPB ), 1, 1, DESCB, 0, 0, 'X', NOUT,
     $               MEM( IPW ) )
      CALL PDLAWRITE( 'SCAEXSOL.dat', N, NRHS, MEM( IPB ), 1, 1, DESCB,
     $                0, 0, MEM( IPW ) )
*
*     Compute residual ||A * X  - B|| / ( ||X|| * ||A|| * eps * N )
      EPS = PDLAMCH( ICTXT, 'Epsilon' )
      ANORM = PDLANGE( 'I', N, N, MEM( IPA ), 1, 1, DESCA, MEM( IPW ) )
      BNORM = PDLANGE( 'I', N, NRHS, MEM( IPB ), 1, 1, DESCB,
     $                 MEM( IPW ) )


      CALL PDGEMM( 'No transpose', 'No transpose', N, NRHS, N, ONE,
     $             MEM( IPACPY ), 1, 1, DESCA, MEM( IPB ), 1, 1, DESCB,
     $             -ONE, MEM( IPX ), 1, 1, DESCX )
      XNORM = PDLANGE( 'I', N, NRHS, MEM( IPX ), 1, 1, DESCX,
     $                 MEM( IPW ) )
      RESID = XNORM / ( ANORM * BNORM * EPS * DBLE( N ) )
      ELAPSED_TIME = MPI_WTIME() - START_TIME * <- added this
*
      IF( MYROW.EQ.0 .AND. MYCOL.EQ.0 ) THEN
         WRITE( NOUT, FMT = * )
         WRITE( NOUT, FMT = * )
     $     '||A * X  - B|| / ( ||X|| * ||A|| * eps * N ) = ', RESID
         WRITE( NOUT, FMT = * )
         IF( RESID.LT.10.0D+0 ) THEN
            WRITE( NOUT, FMT = * ) 'The answer is correct.'
            WRITE( NOUT, FMT = * ) 1000.0*ELAPSED_TIME      * <- added this
         ELSE
            WRITE( NOUT, FMT = * ) 'The answer is suspicious.'
            WRITE( NOUT, FMT = * ) 1000.0*ELAPSED_TIME         * <- added this
         END IF
      END IF

现在我所获得的经过时间似乎并不一致 - 多次运行导致执行时间完全不同。

我使用qsub将其作为群集作业运行。有没有办法通过预订系统获得执行时间，而无需更改代码？

对于我的实验，我需要少量的大块。当我尝试在SCAEX.dat中增加块大小时：

e.g。从：

'ScaLAPACK Example Program 2'
'May 1997'
'SCAEX.out'             output file name (if any)
400                       device out
400                       value of N
400                       value of NRHS
200                       values of NB
2                       values of NPROW
2                       values of NPCOL

为：

'ScaLAPACK Example Program 2'
'May 1997'
'SCAEX.out'             output file name (if any)
400                       device out
400                       value of N
400                       value of NRHS
400                       values of NB
1                       values of NPROW
1                       values of NPCOL

我明白了：

Unable to perform test: need TOTMEM of at least    5126408
Bad MEMORY parameters: going on to next test case.

Answer 1

您可以使用shell命令time代替。如果您的可执行文件a.out在shell脚本中使用。

$ time a.out

然后你可以从std.out

获得时间

源文件中也是TOTMEM = 2000000 < 5126408。

编写可配置的scalapack线性系统求解器，打印执行时间

1 个答案: