194b285447
This BTL accesses the Cisco usNIC Linux device via the Linux verbs API via Unreliable Datagram queue pairs. A few noteworthy points: * This BTL does most of its own fragmentation; it tells the PML that it has a very high max_send_size (much higher than the network MTU). * Since UD fragments are, by definition, unreliable, the usnic BTL handles all of its own reliability via a sliding window approach using the opal_hotel construct and many tricks stolen from the corpus of knowledge surrounding efficient TCP. * There is a fun PML latency-metric based optimization for NUMA awareness of short messages. * Note that this is ''not'' a generic UD verbs BTL; it is specific to the Cisco usNIC device. This commit was SVN r28879.
68 строки
1.7 KiB
C
68 строки
1.7 KiB
C
/*
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* Copyright (c) 2013 Cisco Systems, Inc. All rights reserved.
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* $COPYRIGHT$
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*
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* Additional copyrights may follow
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*
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* $HEADER$
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*/
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#ifndef BTL_USNIC_ACK_H
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#define BTL_USNIC_ACK_H
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#include "ompi_config.h"
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#include "opal/class/opal_hotel.h"
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#include "btl_usnic.h"
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#include "btl_usnic_frag.h"
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#include "btl_usnic_endpoint.h"
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/*
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* Reap an ACK send that is complete
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*/
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void ompi_btl_usnic_ack_complete(ompi_btl_usnic_module_t *module,
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ompi_btl_usnic_ack_segment_t *ack);
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/*
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* Send an ACK
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*/
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void ompi_btl_usnic_ack_send(ompi_btl_usnic_module_t *module,
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ompi_btl_usnic_endpoint_t *endpoint);
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/*
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* Callback for when a send times out without receiving a
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* corresponding ACK
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*/
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void ompi_btl_usnic_ack_timeout(opal_hotel_t *hotel, int room_num,
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void *occupant);
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/*
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* Handle an incoming ACK
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*/
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void ompi_btl_usnic_handle_ack(ompi_btl_usnic_endpoint_t *endpoint,
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ompi_btl_usnic_seq_t ack_seq);
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static inline void
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ompi_btl_usnic_piggyback_ack(
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ompi_btl_usnic_endpoint_t *endpoint,
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ompi_btl_usnic_send_segment_t *sseg)
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{
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/* If ACK is needed, piggy-back it here and send it on */
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if (endpoint->endpoint_ack_needed) {
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ompi_btl_usnic_remove_from_endpoints_needing_ack(endpoint);
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sseg->ss_base.us_btl_header->ack_seq =
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endpoint->endpoint_next_contig_seq_to_recv - 1;
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#if MSGDEBUG1
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opal_output(0, "Piggy-backing ACK for sequence %d\n",
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sseg->ss_base.us_btl_header->ack_seq);
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#endif
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} else {
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sseg->ss_base.us_btl_header->ack_seq = 0;
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}
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}
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#endif /* BTL_USNIC_ACK_H */
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