It is possible that a request handler of RMA request is
called for the second time inside the first called request
handler on the same request.

Consider the following case: a req is queued up in Nemesis
SHM queue with ref count of 2: one is for request completion
and another is for dequeueing from SHM queue. The first
called req handler completed this request and decrement ref
count to 1. This request is still in the queue. However,
within this handler, we trigger the same req handler on the
same request again (for example making progress on SHM queue),
and the second called handler also tries to complete this
request, which leads to the wrong execution.

In this patch we check if request has already been completed
when entering the req handler, to prevent processing the same
request twice. We also move the function finish_op_on_target()
(where the same req handler can be triggered again)
after request completion routine, so that we can mark the
current request as completed before enter the same req handler
for the second time.

Fix #2204

Signed-off-by: Pavan Balaji <balaji@anl.gov>

ReqHandler_GaccumLikeSendComplete is used for GACC-like operations,
including GACC, CAS and FOP. Here we split it into following three
functions:

ReqHandler_GaccumSendComplete
ReqHandler_CASSendComplete
ReqHandler_FOPSendComplete

It is convenient for us to add different actions in future for those
three kinds of operations.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Here we wrap up common action when one RMA op is finished on target
into a function to make code structure cleaner.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Originally do_accumulate_op() only accepts request pointer as
argument which is too restrict to be reused. Here we modify
it to access buffer address, count, datatype and op, so that
it can be reused in more general cases.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

We made a huge change to RMA infrastructure and
a lot of old code can be droped, including separate
handlers for lock-op-unlock, ACCUM_IMMED specific
code, O(p) data structure code, code of lazy issuing,
etc.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

1. Piggyback LOCK request with first IMMED operation.

When we see an IMMED operation, we can always piggyback
LOCK request with that operation to reduce one sync
message of single LOCK request. When packet header of
that operation is received on target, we will try to
acquire the lock and perform that operation. The target
either piggybacks LOCK_GRANTED message with the response
packet (if available), or sends a single LOCK_GRANTED
message back to origin.

2. Rewrite code of manage lock queue.

When the lock request cannot be satisfied on target,
we need to buffer that lock request on target. All we
need to do is enqueuing the packet header, which contains
all information we need after lock is granted. When
the current lock is released, the runtime will goes
over the lock queue and grant the lock to the next
available request. After lock is granted, the runtime
just trigger the packet handler for the second time.

3. Release lock on target side if piggybacking with UNLOCK.

If there are active-message operations to be issued,
we piggyback a UNLOCK flag with the last operation.
When the target recieves it, it will release the current
lock and grant the lock to the next process.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

For FOP operation, all data can be fit into the packet
header, so on origin side we do not need to send separate
data packets, and on target side we do not need request
handler, only packet handler is needed. Similar with FOP
response packet, we can receive all data in FOP resp packet
handler. This patch delete the request handler on target
side and simplify packet handler on target / origin side.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

We add a IMMED data area (16 bytes by default) in
packet header which will contains as much origin
data as possible. If origin can put all data in
packet header, then it no longer needs to send
separate data packet. When target recieves the
packet header, it will first copy data out from
the IMMED data area. If there is still more
data coming, it continues to receive following
packets; if all data is included in header, then
recieving is done.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

During PSCW, when there are active-message operations
to be issued in Win_complete, we piggback a AT_COMPLETE
flag with it so that when target receives it, it can
decrement a counter on target side and detect completion
when target counter reaches zero.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

When the origin wants to do a FLUSH sync, if there are
active-message operations that are going to be issued,
we piggback the FLUSH message with the last operation;
if no such operations, we just send a single FLUSH packet.

If the last operation is a write op (PUT, ACC) or only
a single FLUSH packet is sent, after target recieves it,
target will send back a single FLUSH_ACK packet;
if the last operation contains a read action (GET, GACC, FOP,
CAS), after target receiveds it, target will piggback a
FLUSH_ACK flag with the response packet.

After origin receives the FLUSH_ACK packet or response packet
with FLUSH_ACK flag, it will decrement the counter which
indicates number of outgoing sync messages (FLUSH / UNLOCK).
When that counter reaches zero, origin can know that remote
completion is achieved.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Separate final request handler of PUT, ACC, GACC into three.
Separate derived DT request handler of ACC and GACC into two.

Renaming request handlers as follows:

(1) Normal request handler: it is triggered on target side
    when all data from origin is received.

    It includes:

    ReqHandler_PutRecvComplete --- for PUT
    ReqHandler_AccumRecvComplete --- for ACC
    ReqHandler_GaccumRecvComplete --- for GACC

(2) Derived DT request handler: it is triggered on target
    side when all derived DT info is recieved.

    It includes:

    ReqHandler_PutDerivedDTRecvComplete --- for PUT
    ReqHandler_AccumDerivedDTRecvComplete --- for ACC
    ReqHandler_GaccumDerivedDTRecvComplete --- for GACC

(3) Reponse request handler: it is triggered on target
    side when sending back process is finished in GET-like
    operations.

    It includes:

    ReqHandler_GetSendComplete --- for GET
    ReqHandler_GaccumLikeSendComplete --- for GACC, FOP, CAS

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Xin Zhao authored Nov 02, 2014 and Pavan Balaji committed Nov 03, 2014

We were duplicating information in the operation structure and in the
packet structure when the message is actually issued.  Since most of
the information is the same anyway, this patch just embeds a packet
structure into the operation structure, so that we eliminate unnessary
copy.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Xin Zhao authored Nov 02, 2014 and Pavan Balaji committed Nov 03, 2014

The packet type MPIDI_CH3_PKT_PT_RMA_DONE is used for ACK
of FLUSH / UNLOCK packets. Here we rename it to
MPIDI_CH3_PKT_FLUSH_ACK and modify the related functions
and data structures.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Xin Zhao authored Jul 21, 2014 and Pavan Balaji committed Nov 03, 2014

We were adding an unnecessary dependency on VC structure
declarations in the mpidpkt.h file. The required information
in RMA lock queue is only the rank, but not actual VC.
Here we replace VC with rank.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

Xin Zhao authored Nov 02, 2014 and Pavan Balaji committed Nov 03, 2014

Split RMA functionality into smaller files, and move functions
to where they belong based on the file names.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

req->dev.user_buf points to the data sent from origin process
to target process, and for FOP sometimes it points to the IMMED
area in packet header when data can be fit in packet header.
In such case, we should not free req->dev.user_buf in final
request handler since that data area will be freed by the
runtime when packet header is freed.

In this patch we initialize user_buf to NULL when creating the
request, and set it to NULL when FOP is completed, and avoid free
a NULL pointer in final request handler.

Signed-off-by: Min Si <msi@il.is.s.u-tokyo.ac.jp>

Xin Zhao authored Aug 12, 2014 and Pavan Balaji committed Nov 01, 2014

The original implementation includes an optimization which
allows Win_unlock for exclusive lock to return without
waiting for remote completion. This relys on the
assumption that window memory on target process will not
be accessed by a third party until that target process
finishes all RMA operations and grants the lock to other
processes. However, this assumption is not correct if user
uses assert MPI_MODE_NOCHECK. Consider the following code:

          P0                              P1           P2
    MPI_Win_lock(P1, NULL, exclusive);
    MPI_Put(X);
    MPI_Win_unlock(P1, exclusive);
    MPI_Send (P2);                                MPI_Recv(P0);
                                                  MPI_Win_lock(P1, MODE_NOCHECK, exclusive);
                                                  MPI_Get(X);
                                                  MPI_Win_unlock(P1, exclusive);

Both P0 and P2 issue exclusive lock to P1, and P2 uses assert
MPI_MODE_NOCHECK because the lock should be granted to P2 after
synchronization between P2 and P0. However, in the original
implementation, GET operation on P2 might not get the updated
value since Win_unlock on P0 return without waiting for remote
completion.

In this patch we delete this optimization. In Win_free, since every
Win_unlock guarantees the remote completion, target process no
longer needs to do additional counting works to detect target-side
completion, but only needs to do a global barrier.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

at_completion_counter is used to indicate if all Active Target
operations have completed on this target.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

For GET-like operations, We should increment the Active Target counter
when the process of sending back data is not completed immediately on
target and a response request is created. We should decrement the counter
when the process of sending back data is completed on target side.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

In the original implementation, for GACC/FOP/CAS, the function
MPIDI_CH3_Finish_rma_op_target (includes operations that should
be performed on target when that operation finishes on target)
is not called when that operation real finishes, but is called
after starting send back data.

Here we fix it to make the function called after sending process
on target is completed.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

For Active Target synchronization, the original implementation
does not guarantee the completion of all ops on target side
when Win_wait / Win_fence returns. It is implemented using a
counter, which is decremented when the last operation from that
origin finishes. Win_wait / Win_fence waits until that counter
reaches zero. Problem is that, when the last operation finishes,
the previous GET-like operation (for example with a large data
volume) may have not finished yet. This breaks the semantic of
Win_wait / Win_fence.

Here we fix this by increment the counter whenever we meet a
GET-like operation, and decrement it when that operation finishes
on target side. This will guarantee that when counter reaches
zero and Win_wait / Win_fence returns, all operations are completed
on the target.

Signed-off-by: Pavan Balaji <balaji@anl.gov>

This reverts commit 274a5a70.

We were creating duplicating information in the operation structure
and in the packet structure when the message is actually issued.
Since most of the information is the same anyway, this patch just
embeds a packet structure into the operation structure.

Signed-off-by: Xin Zhao <xinzhao3@illinois.edu>

There are quite a few places where the request cleanup is done via:

MPIU_Object_set_ref(req, 0);
MPIDI_CH3_Request_destroy(req);

when it should be:

MPID_Request_release(req);

This makes the handling more uniform so requests are cleaned up by releasing
references rather than hitting them with the destroy hammer.

Fixes #1664

Signed-off-by: Ken Raffenetti <raffenet@mcs.anl.gov>

Mark those variables exclusively being used for assertions as potentially
unused to avoid compiler warnings when the assertion macro does nothing. These
show up with --enable-fast.

Signed-off-by: Pavan Balaji <balaji@mcs.anl.gov>

Dave Goodell authored Apr 04, 2013 and Rob Latham committed Oct 31, 2013

Also includes random fixes to `-Wshorten-64-to-32` warnings which might
need to be teased out.

Signed-off-by: Pavan Balaji <balaji@mcs.anl.gov>

The check was originally in the ch3 layer, but doesn't seem to use any
ch3 specific information.  This macro will be useful at the upper
layers for optimizations, e.g., in the localcopy routine.

Signed-off-by: Xin Zhao <xinzhao3@illinois.edu>

Xin Zhao authored Jul 22, 2013 and Pavan Balaji committed Jul 28, 2013

If "alloc_shm" is set, it may happen that the target process is doing a RMA operation
from a remote process concurrently with a local process is also doing a RMA operation
on the same target and on overlapping memory location.

Signed-off-by: Pavan Balaji <balaji@mcs.anl.gov>

The single_op_opt flag in the request object was previously used to
track whether an operation is a lock-op-unlock type, for the purposes of
completion.  Tracking this state has been merged into the packet header
flags, so the single_op_opt flag is no longer needed.

Reviewer: goodell

This patch uses packet header flags to piggyback the unlock operation on other
RMA operations.  For most operations, there is no net change.  However, FOP and
GACC, unlock piggybacking was previously not implemented.

Reviewer: goodell

This patch consolidates the synchronization and tracking of RMA operations into
a single routine that is called whenever we complete an operation.  The only
exception are lock-op-unlock operations that are completed from within the lock
operation processing code.

This code is pretty ugly, but it will get cleaner once packet flags are been
added.

Reviewer: goodell

Partially reverted [0b364068] in preparation for incorporating new
piggybacking infrastructure.  This temporarily re-introduces that bug
and it will be fixed again with the new piggybacking patch.

Reviwer: goodell

GACC operations were both piggybacking the unlock message to the origin, and
sending back a PT done packet.  This was causing the origin to be unlocked
twice.  When another lock operation was performed between the GACC and PT done
unlock operations, there was a synchronization race.

Fetch-and-op has been updated to ignore the origin data and perform no
operation when the given op is MPI_NO_OP.

Reviewer: goodell

Reviewer: buntinas

Reviewer: goodell

By setting "indent-tabs-mode:nil" we should hopefully begin to slowly
squeeze out hard tabs from the source without a disruptive (to
downstream projects) whitespace-fixing change.

No reviewer.

Updated the fetch_and_op implementation to have two data transfer paths; one
where data can be embedded in the packet header and one where it is sent
separately.  With this change, the header size is back to 40 bytes.

Reviewer: buntinas

Pulled bit manipulation arithmetic into macros for converting handles to
indices in MPIR_Op and MPIR_Op_check_dtype function pointer tables.

Reviewer: buntinas