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openmpi/ompi/mca/osc/rdma/osc_rdma_request.c
Nathan Hjelm d8df9d414d osc/rdma: add true RDMA one-sided component
This commit adds support for performing one-sided operations over
supported hardware (currently Infiniband and Cray Gemini/Aries). This
component is still undergoing active development.

Current features:

 - Use network atomic operations (fadd, cswap) for implementing
   locking and PSCW synchronization.

 - Aggregate small contiguous puts.

 - Reduced memory footprint by storing window data (pointer, keys,
   etc) at the lowest rank on each node. The data is fetched as each
   process needs to communicate with a new peer. This is a trade-off
   between the performance of the first operation on a peer and the
   memory utilization of a window.

TODO:

 - Add support for the accumulate_ops info key. If it is known that
   the same op or same op/no op is used it may be possible to use
   hardware atomics for fetch-and-op and compare-and-swap.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
2015-09-16 15:01:33 -06:00

75 строки
2.0 KiB
C

/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2011-2012 Sandia National Laboratories. All rights reserved.
* Copyright (c) 2014-2015 Los Alamos National Security, LLC. All rights
* reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "ompi/request/request.h"
#include "ompi/mca/osc/osc.h"
#include "ompi/mca/osc/base/base.h"
#include "ompi/mca/osc/base/osc_base_obj_convert.h"
#include "osc_rdma.h"
#include "osc_rdma_request.h"
static int request_cancel(struct ompi_request_t *request, int complete)
{
return MPI_ERR_REQUEST;
}
static int request_free(struct ompi_request_t **ompi_req)
{
ompi_osc_rdma_request_t *request =
(ompi_osc_rdma_request_t*) *ompi_req;
if (true != request->super.req_complete) {
return MPI_ERR_REQUEST;
}
OMPI_OSC_RDMA_REQUEST_RETURN(request);
*ompi_req = MPI_REQUEST_NULL;
return OMPI_SUCCESS;
}
static int request_complete (struct ompi_request_t *request)
{
ompi_osc_rdma_request_t *parent_request = ((ompi_osc_rdma_request_t *) request)->parent_request;
if (parent_request && 0 == OPAL_THREAD_ADD32 (&parent_request->outstanding_requests, -1)) {
ompi_osc_rdma_request_complete (parent_request, OMPI_SUCCESS);
}
return OMPI_SUCCESS;
}
static void request_construct(ompi_osc_rdma_request_t *request)
{
request->super.req_type = OMPI_REQUEST_WIN;
request->super.req_status._cancelled = 0;
request->super.req_free = request_free;
request->super.req_cancel = request_cancel;
request->super.req_complete_cb = request_complete;
request->parent_request = 0;
OBJ_CONSTRUCT(&request->convertor, opal_convertor_t);
}
static void request_destruct(ompi_osc_rdma_request_t *request)
{
OBJ_DESTRUCT(&request->convertor);
}
OBJ_CLASS_INSTANCE(ompi_osc_rdma_request_t,
ompi_request_t,
request_construct,
request_destruct);