[mpich2-dev] [mpi-all-commits] r3669 - mpich2/branches/dev/knem/src/mpid/ch3/channels/nemesis/nemesis/src

[Dave Goodell]

Bill,

This is a change in a development branch.  For various reasons it has  
(rightly) not undergone the same level of scrutiny that a trunk commit  
would have.  I will make sure that this parameter conforms to the  
pattern before it makes its way to the trunk.

-Dave

On Dec 10, 2008, at 8:22 AM, William Gropp wrote:

> This change reminded me that there are standards in MPICH for  
> parameter handling to provide some uniformity and (in the full case)  
> embedded self documentation.  Its very easy for a large package like  
> MPICH2 to accumulate a wide variety of parameters with different  
> handling and naming conventions, and it is easier on everyone in the  
> long run if these follow a standard form.
>
> In brief, the standard suggests using MPICH_ as the prefix and using  
> a common set of routines that can ensure that the values are  
> available and correct (what happens if I set this value to the  
> string "64k").
>
> Bill
>
> On Dec 9, 2008, at 6:36 PM, bgoglin at mcs.anl.gov wrote:
>
>> Author: bgoglin
>> Date: 2008-12-09 18:36:48 -0600 (Tue, 09 Dec 2008)
>> New Revision: 3669
>>
>> Modified:
>>  mpich2/branches/dev/knem/src/mpid/ch3/channels/nemesis/nemesis/src/ 
>> mpid_nem_lmt_dma.c
>> Log:
>> set NEM_LMT_DMA_THRESHOLD=<n> in the environment to change the DMA  
>> threshold, 2MB by default
>>
>> Modified: mpich2/branches/dev/knem/src/mpid/ch3/channels/nemesis/ 
>> nemesis/src/mpid_nem_lmt_dma.c
>> ===================================================================
>> --- mpich2/branches/dev/knem/src/mpid/ch3/channels/nemesis/nemesis/ 
>> src/mpid_nem_lmt_dma.c	2008-12-09 22:16:00 UTC (rev 3668)
>> +++ mpich2/branches/dev/knem/src/mpid/ch3/channels/nemesis/nemesis/ 
>> src/mpid_nem_lmt_dma.c	2008-12-10 00:36:48 UTC (rev 3669)
>> @@ -50,7 +50,12 @@
>>    int err;
>>    int i;
>>    struct knem_cmd_info info;
>> +    char *env;
>>
>> +    env = getenv("NEM_LMT_DMA_THRESHOLD");
>> +    if (env)
>> +      dma_threshold = atol(env);
>> +
>>    knem_fd = open(KNEM_DEVICE_FILENAME, O_RDWR);
>>    MPIU_ERR_CHKANDJUMP2(knem_fd < 0, mpi_errno, MPI_ERR_OTHER,  
>> "**shm_open",
>>                         "**shm_open %s %d", KNEM_DEVICE_FILENAME,  
>> errno);
>>
>
> William Gropp
> Deputy Director for Research
> Institute for Advanced Computing Applications and Technologies
> Paul and Cynthia Saylor Professor of Computer Science
> University of Illinois Urbana-Champaign
>
>
>
>