On Feb 24, 2010, at 12:16 PM, Aurélien Bouteiller wrote: > btl is the component responsible for a particular type of fabric. Endpoint is > somewhat the instantiation of a btl to reach a particular destination on a > particular fabric, proc is the generic name and properties of a destination.
A few more words here... btl = Byte Transfer Layer. It's our name for the framework that governs one flavor of point-to-point communications in the MPI layer. Components in this framework are used by the ob1 and csum PMLs to effect MPI point-to-point communications (they're used in other ways, too, but let's start at the beginning here...). There are several btl components: tcp, sm (shared memory), self (process loopback), openib (OpenFabrics), ...etc. Each one of these effects communications over a different network type. For purposes of this discussion, "component" == "plugin". The btl plugin is loaded into an MPI process and its component open/query functions are called. If the btl component determines that it wants to run, it returns one or more modules. Typically, btls return a module for every interface that they find. For example, if the openib module finds 2 OpenFabrics device ports, it'll return 2 modules. Hence, we typically describe components as analogous to a C++ class; modules are analogous to instances of that C++ class. Note that in many BTL component comments and variables/fields, they typically use shorthand language such as, "The btl then does this..." Such language almost always refers to a specific module of that btl component. Modules are marshalled by the bml and ob1/csum to make an ordered list of who can talk to whom. Endpoints are data structures used to represent a module's connection to a remote MPI process (proc). Hence, a BTL component can create multiple modules; each module can create lots of endpoints. Each endpoint is tied to a specific remote proc. > Aurelien > > Le 24 févr. 2010 à 09:59, hu yaohui a écrit : > > > Could someone tell me the relationship between proc,endpoint and btl? > > thanks & regards > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel > -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
