WHAT: Open our low-level communication infrastructure by moving all necessary components (btl/rcache/allocator/mpool) down in OPAL
All the components required for inter-process communications are currently deeply integrated in the OMPI layer. Several groups/institutions have express interest in having a more generic communication infrastructure, without all the OMPI layer dependencies. This communication layer should be made available at a different software level, available to all layers in the Open MPI software stack. As an example, our ORTE layer could replace the current OOB and instead use the BTL directly, gaining access to more reactive network interfaces than TCP. Similarly, external software libraries could take advantage of our highly optimized AM (active message) communication layer for their own purpose. UTK with support from Sandia, developped a version of Open MPI where the entire communication infrastucture has been moved down to OPAL (btl/rcache/allocator/mpool). Most of the moved components have been updated to match the new schema, with few exceptions (mainly BTLs where I have no way of compiling/testing them). Thus, the completion of this RFC is tied to being able to completing this move for all BTLs. For this we need help from the rest of the Open MPI community, especially those supporting some of the BTLs. A non-exhaustive list of BTLs that qualify here is: mx, portals4, scif, udapl, ugni, usnic.
This commit was SVN r32317.
Based on a suggestion from George on #31806, use the pre-computed
sizes rather than duplicating the computation math (which may change
someday in the future).
cmr=v1.8.2:ticket=trac:4647
This commit was SVN r31841.
The following Trac tickets were found above:
Ticket 4647 --> https://svn.open-mpi.org/trac/ompi/ticket/4647
MPI_Isend.
I filed an RFC for this optimization some time back. It is a
relatively simple optimization. If the data associated with an
MPI_Isend can be put on the wire without allocating an MPI_Request
then do so. In this case we can legally return omp_request_empty
which will correctly indicate that the request is complete and that is
was not cancelled (these are the only requirements on send requests).
cmr=v1.8.3:reviewer=bosilca
This commit was SVN r31828.
r30343 introduced the optimization of putting the OB1 sendreq and
recvreq on the stack for blocking sends and receives. However, the
requests did not contain enough storage for the data that is normally
immediately ''after'' the request (e.g., BTL data).
This commit changes these requests to be pointers and to use alloca()
to get enough total space for the OB1 request and all the associated
data.
The change is smaller than it looks; most of it is just changing from
"foo.bar" to "foo->bar" notation (etc.).
Submitted by Jeff, reviewed by Nathan. But we want George to look at
this (and get a little soak time on the trunk) before moving to v1.8.
cmr=v1.8.2:reviewer=bosilca
This commit was SVN r31806.
The following SVN revision numbers were found above:
r30343 --> open-mpi/ompi@2b57f4227e
We will track #4568 from the 1.8 CMR.
Closes trac:4568
cmr=v1.8.2:reviewer=jsquyres
This commit was SVN r31535.
The following Trac tickets were found above:
Ticket 4568 --> https://svn.open-mpi.org/trac/ompi/ticket/4568
The problem was caused by the static request optimization. The buffered send case
is much like the isend case in that the request structure may be needed after
MPI_Bsend completes. Fix this case by calling isend and freeing the resulting
request.
cmr=v1.7.5:ticket=trac:4149
This commit was SVN r30601.
The following Trac tickets were found above:
Ticket 4149 --> https://svn.open-mpi.org/trac/ompi/ticket/4149
This change does not appear to increase the small message latency of ping-pong
benchmarks and fixes an issue found by our ibm datatype tests.
Fixes trac:4232
cmr=v1.7.5:ticket=trac:4149
This commit was SVN r30598.
The following Trac tickets were found above:
Ticket 4149 --> https://svn.open-mpi.org/trac/ompi/ticket/4149
Ticket 4232 --> https://svn.open-mpi.org/trac/ompi/ticket/4232
btl sendi functions currently can not handle the descriptor being NULL. The
send inline optimization was assuming (incorrectly) that NULL was ok.
cmr=v1.7.5:ticket=trac:4149
This commit was SVN r30364.
The following Trac tickets were found above:
Ticket 4149 --> https://svn.open-mpi.org/trac/ompi/ticket/4149
Per RFC. There are two optimizations in this commit:
- Allocate requests for blocking sends and receives on the stack. This
bypasses the request free list and saves two atomics on the critical path.
This change improves the small message ping-pong by 50-200ns on both AMD
and Intel CPUs.
- For small messages try to use the btl sendi function before intializing a
send request. If the sendi fails or the btl does not have a sendi function
silently fallback on the standard send path.
cmr=v1.7.5:reviewer=brbarret
This commit was SVN r30343.
value to signal that the operation of retrieving the element from the free list
failed. However in this case the returned pointer was set to NULL as well, so the
error code was redundant. Moreover, this was a continuous source of warnings when
the picky mode is on.
The attached parch remove the rc argument from the OMPI_FREE_LIST_GET and
OMPI_FREE_LIST_WAIT macros, and change to check if the item is NULL instead of
using the return code.
This commit was SVN r28722.
1. The send path get shorter. The BTL is allowed to return > 0 to specify that the
descriptor was pushed to the networks, and that the memory attached to it is
available again for the upper layer. The MCA_BTL_DES_SEND_ALWAYS_CALLBACK flag
can be used by the PML to force the BTL to always trigger the callback.
Unmodified BTL will continue to work as expected, as they will return OMPI_SUCCESS
which force the PML to have exactly the same behavior as before. Some BTLs have
been modified: self, sm, tcp, mx.
2. Add send immediate interface to BTL.
The idea is to have a mechanism of allowing the BTL to take advantage of
send optimizations such as the ability to deliver data "inline". Some
network APIs such as Portals allow data to be sent using a "thin" event
without packing data into a memory descriptor. This interface change
allows the BTL to use such capabilities and allows for other optimizations
in the future. All existing BTLs except for Portals and sm have this interface
set to NULL.
This commit was SVN r18551.
PERUSE_COMM_REQ_ACTIVATE event.
Therefore move the PERUSE_TRACE_COMM_EVENT for this event from
MCA_PML_BASE_SEND_REQUEST_INIT / MCA_PML_BASE_RECV_REQUEST_INIT
to the proper places into pml_ob1_isend.c / pml_ob1_irecv.c right
after the MCA_PML_OB1_SEND_REQUEST_INIT /
MCA_PML_OB1_RECV_REQUEST_INIT.
This commit was SVN r15945.
have to construct/destruct only once. Therefore, the construction will
happens before digging for a PML, while the destruction just before
finalizing the component.
Add some OPAL_LIKELY/OPAL_UNLIKELY.
This commit was SVN r15347.
single threaded builds. In its default configuration, all this does
is ensure that there's at least a good chance of threads building
based on non-threaded development (since the variable names will be
checked). There is also code to make sure that a "mutex" is never
"double locked" when using the conditional macro mutex operations.
This is off by default because there are a number of places in both
ORTE and OMPI where this alarm spews mega bytes of errors on a
simple test. So we have some work to do on our path towards
thread support.
Also removed the macro versions of the non-conditional thread locks,
as the only places they were used, the author of the code intended
to use the conditional thread locks. So now you have upper-case
macros for conditional thread locks and lowercase functions for
non-conditional locks. Simple, right? :).
This commit was SVN r15011.
long ago) supposed to be used as a cache for accessing the PML procs. But in
all of the PMLs the PML proc contain only one field i.e. a pointer to the ompi_proc.
This pointer can be accessed using the c_remote_group easily. Therefore, there is no
meaning of keeping the PML procs around. Slim fast commit ...
This commit was SVN r11730.
We support all the events in the PERUSE specifications, but right now only one event
of each type can be attached to a communicator. This will be worked out in the future.
The events were places in such a way, that we will be able to measure the overhead
for our threading implementation (the cost of the synchronization objects).
This commit was SVN r9500.
to let the PML (or io, more generally the low level request manager)
to have it's own release function (what was before the req_fini). This
function will only be called from the low level while the req_free will
be called from the upper level (MPI layer) in order to mark the request
as not used by the user anymore.
From the request point of view the requests will be marked as inactive
everytime we read their status (true for persistent as well). As
MPI_REQUEST_NULL is already marked as inactive, the test and wait functions
are simpler. The drawback is that now we have to change in the
ompi_request_{test|wait} the req_status of the request once we get it's
status.
This commit was SVN r9290.
- initial support for gm progress thread
- corrected threading issue in pml
- added polling progress for a configurable number of cycles to wait for threaded case
This commit was SVN r9188.
of request we are playing with (send or receive). Therefore, it's useless to have another
switch inside this macro and make the code bigger. Now, we have 2 versions
MCA_PML_OB1_SEND_REQUEST_FREE and MCA_PML_OB1_RECV_REQUEST_FREE.
This commit was SVN r8945.
