Re: [myrinet] Re: [Myricom help #8298] smpi_post_send_ok_to_send_out got corrupted handle

Hi Oleg,

"Oleg I. Vdovikin" wrote:
> 
> Hi,
> 
>     there still no response from Myricom Technical Support...

Thanksgiving is one of the rare national hollidays in the US, so 
a lot of people used the occasion to take some vacation last week. 
I am sorry for the delay: your email has been forwarded to me 
but my email queue was quite impressive when I came back yesterday.

There is 2 people (Ruth and Susan) working full time for the Myricom 
support: the processing time is usually pretty good, except when 
everybody is away as it was the case last week.
 
>     BTW, attached please find two patches against both mpich-1.2..8 &
> mpich-1.2.1..7 which fixes Alpha (and IA64 as seems) alignment &
> MPID_PKT_FLOW packet length errors. Without these patches most programs
> crashed during smp operations.

Your analysis is exactely right. Offsets in the shared memory receive 
queue should always use the full type of the packet, not the sum of 
the fields. I cleaned some part of the code in this way a few 
months ago, for alignement issue on Alpha also. 

I did not look carefully in the flow control code at that time. I will 
replace all references to sizes of packets' fields (like sizeof(void *)) 
by the reference to the full type (much easier when adding fields into 
packet types). I will also changed the SMPI_PKT_BASIC definition to shrink 
the size of some fields (mode and lrank can fit in 16 bits). SMPI_PKT_BASIC 
would then be 8 bytes aligned (it does not matter if all the offsets 
use full type sizes) and the latency a little bit lower.
 
>     Please consider applying this patches to the source tree.

I have corrected the CVS tree. It will be on the next release (need 
to finish the MPD integration and the gm_send/gm_directed_send 
failover before to release).
Myricom support will put the patch on the Web and an entry in the 
FAQ.

This bug has escaped the regression test because the test checking the 
flow control was run only on x86. I will add it to the test suite on 
alpha/IA64.

Thanks for the report.

Patrick

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|   Patrick Geoffray, Ph.D.      [email protected] 
|   Myricom, Inc.                http://www.myri.com
|   Cell:  865-389-8852          685 Emory Valley Rd (B)
|   Phone: 865-425-0978          Oak Ridge, TN 37830
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