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Subject: Re: [OMPI devel] [OMPI svn] svn:open-mpi r31577 - trunk/ompi/mca/rte/base
From: Ralph Castain (rhc_at_[hidden])
Date: 2014-04-30 18:46:28


George makes a fair point - I was unaware they were hashing down to the opal_identifier_t. Only real requirement is that there be some way to reduce to 64-bits when accessing the common data.

I think the usnic BTL may have an issue with that approach, so maybe some way of "unhashing" will be required?

On Apr 30, 2014, at 3:42 PM, Jeff Squyres (jsquyres) <jsquyres_at_[hidden]> wrote:

> On Apr 30, 2014, at 6:35 PM, George Bosilca <bosilca_at_[hidden]> wrote:
>
>> Puzzling. We survived so far without such a requirement.
>
> Ralph tells me that this is a requirement. So I figured we should check for it.
>
>> In the BTLs where we needed a 64 bits entity corresponding to the ompi_process_name_t we took advantage of the ompi_rte_hash_name function. This function is supposed to convert from an ompi_process_name_t to a uint64_t (in fact an opal_identifier_t) which can be then used to handle hash tables.
>
> ...I don't really care, either way. I'll do whatever you guys tell me to do here. :-)
>
> I put that assert there because Ralph told me it was a requirement, and I now have code in the usnic BTL that is doing a memcpy from a union uint64_t member to an ompi_process_name_t, and it assumes that the sizes are guaranteed to be the same.
>
> If we want to do it some other way, that's fine with me, too.
>
>
>> George.
>>
>>
>> On Apr 30, 2014, at 18:12 , svn-commit-mailer_at_[hidden] wrote:
>>
>>> Author: jsquyres (Jeff Squyres)
>>> Date: 2014-04-30 18:12:54 EDT (Wed, 30 Apr 2014)
>>> New Revision: 31577
>>> URL: https://svn.open-mpi.org/trac/ompi/changeset/31577
>>>
>>> Log:
>>> rte_base_frame.c: add sanity check to ensure proper sizes
>>>
>>> There's a requirement in several places (e.g., opal dstore) that
>>> sizeof(ompi_process_name_t) -- which comes from the compile-time
>>> selected ompi/mca/rte component -- is equal to sizeof(uint64_t). If
>>> it's not, Bad Things will happen.
>>>
>>> So put an assert here to catch that case.
>>>
>>> Text files modified:
>>> trunk/ompi/mca/rte/base/rte_base_frame.c | 10 +++++++++-
>>> 1 files changed, 9 insertions(+), 1 deletions(-)
>>>
>>> Modified: trunk/ompi/mca/rte/base/rte_base_frame.c
>>> ==============================================================================
>>> --- trunk/ompi/mca/rte/base/rte_base_frame.c Wed Apr 30 18:10:30 2014 (r31576)
>>> +++ trunk/ompi/mca/rte/base/rte_base_frame.c 2014-04-30 18:12:54 EDT (Wed, 30 Apr 2014) (r31577)
>>> @@ -1,6 +1,7 @@
>>> /*
>>> * Copyright (c) 2012-2013 Los Alamos National Security, LLC.
>>> * All rights reserved.
>>> + * Copyright (c) 2014 Cisco Systems, Inc. All rights reserved.
>>> * $COPYRIGHT$
>>> *
>>> * Additional copyrights may follow
>>> @@ -12,6 +13,7 @@
>>> #include "ompi_config.h"
>>> #include "ompi/constants.h"
>>>
>>> +#include "opal_stdint.h"
>>> #include "opal/util/output.h"
>>> #include "opal/mca/mca.h"
>>> #include "opal/mca/base/base.h"
>>> @@ -36,7 +38,13 @@
>>> static int ompi_rte_base_open(mca_base_open_flag_t flags)
>>> {
>>> /* Open up all available components */
>>> - return mca_base_framework_components_open(&ompi_rte_base_framework, flags);
>>> + int ret = mca_base_framework_components_open(&ompi_rte_base_framework, flags);
>>> +
>>> + /* Sanity check. Many things will break if this is not true
>>> + (e.g., opal dstore needs this to be true). */
>>> + assert(sizeof(ompi_process_name_t) == sizeof(uint64_t));
>>> +
>>> + return ret;
>>> }
>>>
>>> MCA_BASE_FRAMEWORK_DECLARE(ompi, rte, "OMPI Run-Time Environment Interface", NULL,
>>> _______________________________________________
>>> svn mailing list
>>> svn_at_[hidden]
>>> http://www.open-mpi.org/mailman/listinfo.cgi/svn
>>
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>
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
>
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