fi_getinfo(3) Libfabric v1.15.1 fi_getinfo(3) NAME fi_getinfo, fi_freeinfo - Obtain / free fabric interface information fi_allocinfo, fi_dupinfo - Allocate / duplicate an fi_info structure SYNOPSIS #include <rdma/fabric.h> int fi_getinfo(int version, const char *node, const char *service, uint64_t flags, const struct fi_info *hints, struct fi_info **info); void fi_freeinfo(struct fi_info *info); struct fi_info *fi_allocinfo(void); struct fi_info *fi_dupinfo(const struct fi_info *info); ARGUMENTS version Interface version requested by application. node Optional, name or fabric address to resolve. service Optional, service name or port number of address. flags Operation flags for the fi_getinfo call. hints Reference to an fi_info structure that specifies criteria for se- lecting the returned fabric information. info A pointer to a linked list of fi_info structures containing response information. DESCRIPTION fi_getinfo returns information about available fabric services for reaching specified node or service, subject to any provided hints. Callers may specify NULL for node, service, and hints in order to retrieve information about what providers are available and their optimal usage models. If no matching fabric information is available, info will be set to NULL and the call will return -FI_ENODATA. Based on the input hints, node, and service parameters, a list of fabric domains and endpoints will be returned. Each fi_info structure will de- scribe an endpoint that meets the application's specified communication criteria. Each endpoint will be associated with a domain. Applications can restrict the number of returned endpoints by including additional cri- teria in their search hints. Relaxing or eliminating input hints will in- crease the number and type of endpoints that are available. Providers that return multiple endpoints to a single fi_getinfo call should return the endpoints that are highest performing first. Providers may indicate that an endpoint and domain can support additional capabilities than those re- quested by the user only if such support will not adversely affect applica- tion performance or security. The version parameter is used by the application to request the desired version of the interfaces. The version determines the format of all data structures used by any of the fabric interfaces. Applications should use the FI_VERSION(major, minor) macro to indicate the version, with hard-coded integer values for the major and minor values. The FI_MAJOR_VERSION and FI_MINOR_VERSION enum values defined in fabric.h specify the latest version of the installed library. However, it is recommended that the integer val- ues for FI_MAJOR_VERSION and FI_MINOR_VERSION be used, rather than refer- encing the enum types in order to ensure compatibility with future versions of the library. This protects against the application being built from source against a newer version of the library that introduces new fields to data structures, which would not be initialized by the application. Node, service, or hints may be provided, with any combination being sup- ported. If node is provided, fi_getinfo will attempt to resolve the fabric address to the given node. If node is not given, fi_getinfo will attempt to resolve the fabric addressing information based on the provided hints. Node is commonly used to provide a network address (such as an IP address) or hostname. Service is usually associated with a transport address (such as a TCP port number). Node and service parameters may be mapped by providers to native fabric addresses. Applications may also pass in an FI_ADDR_STR formatted address (see format details below) as the node para- meter. In such cases, the service parameter must be NULL. The hints parameter, if provided, may be used to limit the resulting output as indicated below. As a general rule, specifying a non-zero value for in- put hints indicates that a provider must support the requested value or fail the operation with -FI_ENODATA. With the exception of mode bits, hints that are set to zero are treated as a wildcard. A zeroed hint value results in providers either returning a default value or a value that works best for their implementation. Mode bits that are set to zero indicate the application does not support any modes. The caller must call fi_freeinfo to release fi_info structures returned by this call. The fi_allocinfo call will allocate and zero an fi_info structure and all related substructures. The fi_dupinfo will duplicate a single fi_info structure and all the substructures within it. FI_INFO struct fi_info { struct fi_info *next; uint64_t caps; uint64_t mode; uint32_t addr_format; size_t src_addrlen; size_t dest_addrlen; void *src_addr; void *dest_addr; fid_t handle; struct fi_tx_attr *tx_attr; struct fi_rx_attr *rx_attr; struct fi_ep_attr *ep_attr; struct fi_domain_attr *domain_attr; struct fi_fabric_attr *fabric_attr; struct fid_nic *nic; }; next Pointer to the next fi_info structure in the list. Will be NULL if no more structures exist. caps - fabric interface capabilities If specified, indicates the desired capabilities of the fabric in- terfaces. Supported capabilities are listed in the Capabilities section below. mode Operational modes supported by the application. See the Mode sec- tion below. addr_format - address format If specified, indicates the format of addresses referenced by the fabric interfaces and data structures. Supported formats are listed in the Addressing formats section below. src_addrlen - source address length Indicates the length of the source address. This value must be > 0 if src_addr is non-NULL. This field will be ignored in hints if FI_SOURCE flag is set, or src_addr is NULL. dest_addrlen - destination address length Indicates the length of the destination address. This value must be > 0 if dest_addr is non-NULL. This field will be ignored in hints unless the node and service parameters are NULL or FI_SOURCE flag is set, or if dst_addr is NULL. src_addr - source address If specified, indicates the source address. This field will be ig- nored in hints if FI_SOURCE flag is set. On output a provider shall return an address that corresponds to the indicated fabric, domain, node, and/or service fields. The format of the address is indicated by the returned addr_format field. Note that any returned address is only used when opening a local endpoint. The address is not guaranteed to be usable by a peer process. dest_addr - destination address If specified, indicates the destination address. This field will be ignored in hints unless the node and service parameters are NULL or FI_SOURCE flag is set. If FI_SOURCE is not specified, on output a provider shall return an address the corresponds to the indicated node and/or service fields, relative to the fabric and domain. Note that any returned address is only usable locally. handle - provider context handle The use of this field is operation specific. If hints->handle is set to struct fid_pep, the hints->handle will be copied to info->handle on output from fi_getinfo. Other values of hints->han- dle will be handled in a provider specific manner. The fi_info::handle field is also used by fi_endpoint() and fi_reject() calls when processing connection requests or to inherit another end- point's attributes. See fi_eq(3), fi_reject(3), and fi_endpoint(3). The info->handle field will be ignored by fi_dupinfo and fi_free- info. tx_attr - transmit context attributes Optionally supplied transmit context attributes. Transmit context attributes may be specified and returned as part of fi_getinfo. When provided as hints, requested values of struct fi_tx_ctx_attr should be set. On output, the actual transmit context attributes that can be provided will be returned. Output values will be greater than or equal to the requested input values. rx_attr - receive context attributes Optionally supplied receive context attributes. Receive context at- tributes may be specified and returned as part of fi_getinfo. When provided as hints, requested values of struct fi_rx_ctx_attr should be set. On output, the actual receive context attributes that can be provided will be returned. Output values will be greater than or or equal to the requested input values. ep_attr - endpoint attributes Optionally supplied endpoint attributes. Endpoint attributes may be specified and returned as part of fi_getinfo. When provided as hints, requested values of struct fi_ep_attr should be set. On out- put, the actual endpoint attributes that can be provided will be re- turned. Output values will be greater than or equal to requested input values. See fi_endpoint(3) for details. domain_attr - domain attributes Optionally supplied domain attributes. Domain attributes may be specified and returned as part of fi_getinfo. When provided as hints, requested values of struct fi_domain_attr should be set. On output, the actual domain attributes that can be provided will be returned. Output values will be greater than or equal to requested input values. See fi_domain(3) for details. fabric_attr - fabric attributes Optionally supplied fabric attributes. Fabric attributes may be specified and returned as part of fi_getinfo. When provided as hints, requested values of struct fi_fabric_attr should be set. On output, the actual fabric attributes that can be provided will be returned. See fi_fabric(3) for details. nic - network interface details Optional attributes related to the hardware NIC associated with the specified fabric, domain, and endpoint data. This field is only valid for providers where the corresponding attributes are closely associated with a hardware NIC. See fi_nic(3) for details. CAPABILITIES Interface capabilities are obtained by OR-ing the following flags together. If capabilities in the hint parameter are set to 0, the underlying provider will return the set of capabilities which are supported. Otherwise, providers will return data matching the specified set of capabilities. Providers may indicate support for additional capabilities beyond those re- quested when the use of expanded capabilities will not adversely affect performance or expose the application to communication beyond that which was requested. Applications may use this feature to request a minimal set of requirements, then check the returned capabilities to enable additional optimizations. FI_ATOMIC Specifies that the endpoint supports some set of atomic operations. Endpoints supporting this capability support operations defined by struct fi_ops_atomic. In the absence of any relevant flags, FI_ATOMIC implies the ability to initiate and be the target of re- mote atomic reads and writes. Applications can use the FI_READ, FI_WRITE, FI_REMOTE_READ, and FI_REMOTE_WRITE flags to restrict the types of atomic operations supported by an endpoint. FI_COLLECTIVE Requests support for collective operations. Endpoints that support this capability support the collective operations defined in fi_col- lective(3). FI_DIRECTED_RECV Requests that the communication endpoint use the source address of an incoming message when matching it with a receive buffer. If this capability is not set, then the src_addr parameter for msg and tagged receive operations is ignored. FI_FENCE Indicates that the endpoint support the FI_FENCE flag on data trans- fer operations. Support requires tracking that all previous trans- mit requests to a specified remote endpoint complete prior to initi- ating the fenced operation. Fenced operations are often used to en- force ordering between operations that are not otherwise guaranteed by the underlying provider or protocol. FI_HMEM Specifies that the endpoint should support transfers to and from de- vice memory. FI_LOCAL_COMM Indicates that the endpoint support host local communication. This flag may be used in conjunction with FI_REMOTE_COMM to indicate that local and remote communication are required. If neither FI_LO- CAL_COMM or FI_REMOTE_COMM are specified, then the provider will in- dicate support for the configuration that minimally affects perfor- mance. Providers that set FI_LOCAL_COMM but not FI_REMOTE_COMM, for example a shared memory provider, may only be used to communication between processes on the same system. FI_MSG Specifies that an endpoint should support sending and receiving mes- sages or datagrams. Message capabilities imply support for send and/or receive queues. Endpoints supporting this capability support operations defined by struct fi_ops_msg. The caps may be used to specify or restrict the type of messaging opera- tions that are supported. In the absence of any relevant flags, FI_MSG im- plies the ability to send and receive messages. Applications can use the FI_SEND and FI_RECV flags to optimize an endpoint as send-only or re- ceive-only. FI_MULTICAST Indicates that the endpoint support multicast data transfers. This capability must be paired with FI_MSG. Applications can use FI_SEND and FI_RECV to optimize multicast as send-only or receive-only. FI_MULTI_RECV Specifies that the endpoint must support the FI_MULTI_RECV flag when posting receive buffers. FI_NAMED_RX_CTX Requests that endpoints which support multiple receive contexts al- low an initiator to target (or name) a specific receive context as part of a data transfer operation. FI_READ Indicates that the user requires an endpoint capable of initiating reads against remote memory regions. This flag requires that FI_RMA and/or FI_ATOMIC be set. FI_RECV Indicates that the user requires an endpoint capable of receiving message data transfers. Message transfers include base message op- erations as well as tagged message functionality. FI_REMOTE_COMM Indicates that the endpoint support communication with endpoints lo- cated at remote nodes (across the fabric). See FI_LOCAL_COMM for additional details. Providers that set FI_REMOTE_COMM but not FI_LOCAL_COMM, for example NICs that lack loopback support, cannot be used to communicate with processes on the same system. FI_REMOTE_READ Indicates that the user requires an endpoint capable of receiving read memory operations from remote endpoints. This flag requires that FI_RMA and/or FI_ATOMIC be set. FI_REMOTE_WRITE Indicates that the user requires an endpoint capable of receiving write memory operations from remote endpoints. This flag requires that FI_RMA and/or FI_ATOMIC be set. FI_RMA Specifies that the endpoint should support RMA read and write opera- tions. Endpoints supporting this capability support operations de- fined by struct fi_ops_rma. In the absence of any relevant flags, FI_RMA implies the ability to initiate and be the target of remote memory reads and writes. Applications can use the FI_READ, FI_WRITE, FI_REMOTE_READ, and FI_REMOTE_WRITE flags to restrict the types of RMA operations supported by an endpoint. FI_RMA_EVENT Requests that an endpoint support the generation of completion events when it is the target of an RMA and/or atomic operation. This flag requires that FI_REMOTE_READ and/or FI_REMOTE_WRITE be en- abled on the endpoint. FI_RMA_PMEM Indicates that the provider is `persistent memory aware' and sup- ports RMA operations to and from persistent memory. Persistent mem- ory aware providers must support registration of memory that is backed by non- volatile memory, RMA transfers to/from persistent memory, and enhanced completion semantics. This flag requires that FI_RMA be set. This capability is experimental. FI_SEND Indicates that the user requires an endpoint capable of sending mes- sage data transfers. Message transfers include base message opera- tions as well as tagged message functionality. FI_SHARED_AV Requests or indicates support for address vectors which may be shared among multiple processes. FI_SOURCE Requests that the endpoint return source addressing data as part of its completion data. This capability only applies to connectionless endpoints. Note that returning source address information may re- quire that the provider perform address translation and/or look-up based on data available in the underlying protocol in order to pro- vide the requested data, which may adversely affect performance. The performance impact may be greater for address vectors of type FI_AV_TABLE. FI_SOURCE_ERR Must be paired with FI_SOURCE. When specified, this requests that raw source addressing data be returned as part of completion data for any address that has not been inserted into the local address vector. Use of this capability may require the provider to validate incoming source address data against addresses stored in the local address vector, which may adversely affect performance. FI_TAGGED Specifies that the endpoint should handle tagged message transfers. Tagged message transfers associate a user-specified key or tag with each message that is used for matching purposes at the remote side. Endpoints supporting this capability support operations defined by struct fi_ops_tagged. In the absence of any relevant flags, FI_TAGGED implies the ability to send and receive tagged messages. Applications can use the FI_SEND and FI_RECV flags to optimize an endpoint as send-only or receive-only. FI_TRIGGER Indicates that the endpoint should support triggered operations. Endpoints support this capability must meet the usage model as de- scribed by fi_trigger(3). FI_VARIABLE_MSG Requests that the provider must notify a receiver when a variable length message is ready to be received prior to attempting to place the data. Such notification will include the size of the message and any associated message tag (for FI_TAGGED). See `Variable Length Messages' in fi_msg.3 for full details. Variable length mes- sages are any messages larger than an endpoint configurable size. This flag requires that FI_MSG and/or FI_TAGGED be set. FI_WRITE Indicates that the user requires an endpoint capable of initiating writes against remote memory regions. This flag requires that FI_RMA and/or FI_ATOMIC be set. FI_XPU Specifies that the endpoint should support transfers that may be initiated from heterogenous computation devices, such as GPUs. This flag requires that FI_TRIGGER be set. For additional details on XPU triggers see fi_trigger(3). Capabilities may be grouped into three general categories: primary, sec- ondary, and primary modifiers. Primary capabilities must explicitly be re- quested by an application, and a provider must enable support for only those primary capabilities which were selected. Primary modifiers are used to limit a primary capability, such as restricting an endpoint to being send-only. If no modifiers are specified for an applicable capability, all relevant modifiers are assumed. See above definitions for details. Secondary capabilities may optionally be requested by an application. If requested, a provider must support the capability or fail the fi_getinfo request (FI_ENODATA). A provider may optionally report non-selected sec- ondary capabilities if doing so would not compromise performance or secu- rity. Primary capabilities: FI_MSG, FI_RMA, FI_TAGGED, FI_ATOMIC, FI_MULTICAST, FI_NAMED_RX_CTX, FI_DIRECTED_RECV, FI_VARIABLE_MSG, FI_HMEM, FI_COLLECTIVE, FI_XPU Primary modifiers: FI_READ, FI_WRITE, FI_RECV, FI_SEND, FI_REMOTE_READ, FI_REMOTE_WRITE Secondary capabilities: FI_MULTI_RECV, FI_SOURCE, FI_RMA_EVENT, FI_SHARED_AV, FI_TRIGGER, FI_FENCE, FI_LOCAL_COMM, FI_REMOTE_COMM, FI_SOURCE_ERR, FI_RMA_PMEM. MODE The operational mode bits are used to convey requirements that an applica- tion must adhere to when using the fabric interfaces. Modes specify opti- mal ways of accessing the reported endpoint or domain. Applications that are designed to support a specific mode of operation may see improved per- formance when that mode is desired by the provider. It is recommended that providers support applications that disable any provider preferred modes. On input to fi_getinfo, applications set the mode bits that they support. On output, providers will clear mode bits that are not necessary to achieve high-performance. Mode bits that remain set indicate application require- ments for using the fabric interfaces created using the returned fi_info. The set of modes are listed below. If a NULL hints structure is provided, then the provider's supported set of modes will be returned in the info structure(s). FI_ASYNC_IOV Applications can reference multiple data buffers as part of a single operation through the use of IO vectors (SGEs). Typically, the con- tents of an IO vector are copied by the provider into an internal buffer area, or directly to the underlying hardware. However, when a large number of IOV entries are supported, IOV buffering may have a negative impact on performance and memory consumption. The FI_ASYNC_IOV mode indicates that the application must provide the buffering needed for the IO vectors. When set, an application must not modify an IO vector of length > 1, including any related memory descriptor array, until the associated operation has completed. FI_BUFFERED_RECV The buffered receive mode bit indicates that the provider owns the data buffer(s) that are accessed by the networking layer for re- ceived messages. Typically, this implies that data must be copied from the provider buffer into the application buffer. Applications that can handle message processing from network allocated data buffers can set this mode bit to avoid copies. For full details on application requirements to support this mode, see the `Buffered Re- ceives' section in fi_msg(3). This mode bit applies to FI_MSG and FI_TAGGED receive operations. FI_CONTEXT Specifies that the provider requires that applications use struct fi_context as their per operation context parameter for operations that generated full completions. This structure should be treated as opaque to the application. For performance reasons, this struc- ture must be allocated by the user, but may be used by the fabric provider to track the operation. Typically, users embed struct fi_context within their own context structure. The struct fi_con- text must remain valid until the corresponding operation completes or is successfully canceled. As such, fi_context should NOT be al- located on the stack. Doing so is likely to result in stack corrup- tion that will be difficult to debug. Users should not update or interpret the fields in this structure, or reuse it until the origi- nal operation has completed. If an operation does not generate a completion (i.e. the endpoint was configured with FI_SELECTIVE_COM- PLETION and the operation was not initiated with the FI_COMPLETION flag) then the context parameter is ignored by the fabric provider. The structure is specified in rdma/fabric.h. FI_CONTEXT2 This bit is similar to FI_CONTEXT, but doubles the provider's re- quirement on the size of the per context structure. When set, this specifies that the provider requires that applications use struct fi_context2 as their per operation context parameter. Or, option- ally, an application can provide an array of two fi_context struc- tures (e.g. struct fi_context[2]) instead. The requirements for us- ing struct fi_context2 are identical as defined for FI_CONTEXT above. FI_LOCAL_MR The provider is optimized around having applications register memory for locally accessed data buffers. Data buffers used in send and receive operations and as the source buffer for RMA and atomic oper- ations must be registered by the application for access domains opened with this capability. This flag is defined for compatibility and is ignored if the application version is 1.5 or later and the domain mr_mode is set to anything other than FI_MR_BASIC or FI_MR_SCALABLE. See the domain attribute mr_mode fi_domain(3) and fi_mr(3). FI_MSG_PREFIX Message prefix mode indicates that an application will provide buffer space in front of all message send and receive buffers for use by the provider. Typically, the provider uses this space to im- plement a protocol, with the protocol headers being written into the prefix area. The contents of the prefix space should be treated as opaque. The use of FI_MSG_PREFIX may improve application perfor- mance over certain providers by reducing the number of IO vectors referenced by underlying hardware and eliminating provider buffer allocation. FI_MSG_PREFIX only applies to send and receive operations, including tagged sends and receives. RMA and atomics do not require the application to pro- vide prefix buffers. Prefix buffer space must be provided with all sends and receives, regardless of the size of the transfer or other transfer op- tions. The ownership of prefix buffers is treated the same as the corre- sponding message buffers, but the size of the prefix buffer is not counted toward any message limits, including inject. Applications that support prefix mode must supply buffer space before their own message data. The size of space that must be provided is specified by the msg_prefix_size endpoint attribute. Providers are required to define a msg_prefix_size that is a multiple of 8 bytes. Additionally, applications may receive provider generated packets that do not contain application data. Such received messages will indicate a transfer size of that is equal to or smaller than msg_prefix_size. The buffer pointer given to all send and receive operations must point to the start of the prefix region of the buffer (as opposed to the payload). For scatter-gather send/recv operations, the prefix buffer must be a con- tiguous region, though it may or may not be directly adjacent to the pay- load portion of the buffer. FI_NOTIFY_FLAGS_ONLY This bit indicates that general completion flags may not be set by the provider, and are not needed by the application. If specified, completion flags which simply report the type of operation that com- pleted (e.g. send or receive) may not be set. However, completion flags that are used for remote notifications will still be set when applicable. See fi_cq(3) for details on which completion flags are valid when this mode bit is enabled. FI_RESTRICTED_COMP This bit indicates that the application will only share completion queues and counters among endpoints, transmit contexts, and receive contexts that have the same set of capability flags. FI_RX_CQ_DATA This mode bit only applies to data transfers that set FI_RE- MOTE_CQ_DATA. When set, a data transfer that carries remote CQ data will consume a receive buffer at the target. This is true even for operations that would normally not consume posted receive buffers, such as RMA write operations. ADDRESSING FORMATS Multiple fabric interfaces take as input either a source or destination ad- dress parameter. This includes struct fi_info (src_addr and dest_addr), CM calls (getname, getpeer, connect, join, and leave), and AV calls (insert, lookup, and straddr). The fi_info addr_format field indicates the expected address format for these operations. A provider may support one or more of the following addressing formats. In some cases, a selected addressing format may need to be translated or mapped into an address which is native to the fabric. See fi_av(3). FI_ADDR_BGQ Address is an IBM proprietary format that is used with their Blue Gene Q systems. FI_ADDR_EFA Address is an Amazon Elastic Fabric Adapter (EFA) proprietary for- mat. FI_ADDR_GNI Address is a Cray proprietary format that is used with their GNI protocol. FI_ADDR_PSMX Address is an Intel proprietary format used with their Performance Scaled Messaging protocol. FI_ADDR_PSMX2 Address is an Intel proprietary format used with their Performance Scaled Messaging protocol version 2. FI_ADDR_PSMX3 Address is an Intel proprietary format used with their Performance Scaled Messaging protocol version 3. FI_ADDR_STR Address is a formatted character string. The length and content of the string is address and/or provider specific, but in general fol- lows a URI model: address_format[://[node][:[service][/[field3]...][?[key=value][&k2=v2]...]]] Examples: - fi_sockaddr://10.31.6.12:7471 - fi_sock- addr_in6://[fe80::6:12]:7471 - fi_sockaddr://10.31.6.12:7471?qos=3 Since the string formatted address does not contain any provider informa- tion, the prov_name field of the fabric attribute structure should be used to filter by provider if necessary. FI_FORMAT_UNSPEC FI_FORMAT_UNSPEC indicates that a provider specific address format should be selected. Provider specific addresses may be protocol specific or a vendor proprietary format. Applications that select FI_FORMAT_UNSPEC should be prepared to treat returned addressing data as opaque. FI_FORMAT_UNSPEC targets apps which make use of an out of band address exchange. Applications which use FI_FORMAT_UN- SPEC may use fi_getname() to obtain a provider specific address as- signed to an allocated endpoint. FI_SOCKADDR Address is of type sockaddr. The specific socket address format will be determined at run time by interfaces examining the sa_family field. FI_SOCKADDR_IB Address is of type sockaddr_ib (defined in Linux kernel source) FI_SOCKADDR_IN Address is of type sockaddr_in (IPv4). FI_SOCKADDR_IN6 Address is of type sockaddr_in6 (IPv6). FI_ADDR_PSMX Address is an Intel proprietary format that is used with their PSMX (extended performance scaled messaging) protocol. FLAGS The operation of the fi_getinfo call may be controlled through the use of input flags. Valid flags include the following. FI_NUMERICHOST Indicates that the node parameter is a numeric string representation of a fabric address, such as a dotted decimal IP address. Use of this flag will suppress any lengthy name resolution protocol. FI_PROV_ATTR_ONLY Indicates that the caller is only querying for what providers are potentially available. All providers will return exactly one fi_info struct, regardless of whether that provider is usable on the current platform or not. The returned fi_info struct will contain default values for all members, with the exception of fabric_attr. The fabric_attr member will have the prov_name and prov_version val- ues filled in. FI_SOURCE Indicates that the node and service parameters specify the local source address to associate with an endpoint. If specified, either the node and/or service parameter must be non-NULL. This flag is often used with passive endpoints. RETURN VALUE fi_getinfo() returns 0 on success. On error, fi_getinfo() returns a nega- tive value corresponding to fabric errno. Fabric errno values are defined in rdma/fi_errno.h. fi_allocinfo() returns a pointer to a new fi_info structure on success, or NULL on error. fi_dupinfo() duplicates a single fi_info structure and all the substructures within it, returning a pointer to the new fi_info struc- ture on success, or NULL on error. Both calls require that the returned fi_info structure be freed via fi_freeinfo(). ERRORS FI_EBADFLAGS The specified endpoint or domain capability or operation flags are invalid. FI_ENODATA Indicates that no providers could be found which support the re- quested fabric information. FI_ENOMEM Indicates that there was insufficient memory to complete the opera- tion. NOTES If hints are provided, the operation will be controlled by the values that are supplied in the various fields (see section on fi_info). Applications that require specific communication interfaces, domains, capabilities or other requirements, can specify them using fields in hints. Libfabric re- turns a linked list in info that points to a list of matching interfaces. info is set to NULL if there are no communication interfaces or none match the input hints. If node is provided, fi_getinfo will attempt to resolve the fabric address to the given node. If node is not provided, fi_getinfo will attempt to re- solve the fabric addressing information based on the provided hints. The caller must call fi_freeinfo to release fi_info structures returned by fi_getinfo. If neither node, service or hints are provided, then fi_getinfo simply re- turns the list all available communication interfaces. Multiple threads may call fi_getinfo simultaneously, without any require- ment for serialization. SEE ALSO fi_open(3), fi_endpoint(3), fi_domain(3), fi_nic(3) fi_trigger(3) AUTHORS OpenFabrics. Libfabric Programmer's Manual 2021-11-20 fi_getinfo(3)
NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | FI_INFO | CAPABILITIES | MODE | ADDRESSING FORMATS | FLAGS | RETURN VALUE | ERRORS | NOTES | SEE ALSO | AUTHORS
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