Anders Logg wrote: > On Sun, Mar 14, 2010 at 07:39:45AM +0000, Garth N. Wells wrote: >> >> Anders Logg wrote: >>> On Fri, Mar 12, 2010 at 06:58:22PM -0000, [email protected] wrote: >>>> ------------------------------------------------------------ >>>> revno: 4635 >>>> committer: Garth N. Wells <[email protected]> >>>> branch nick: dolfin-all >>>> timestamp: Fri 2010-03-12 18:53:05 +0000 >>>> message: >>>> Work on reading Vectors in parallel. Some issues to resolve still. >>>> >>>> Some issues: >>>> - How should files be named when in parallel? >>>> - Should we have a 'master' xml file which points to the files >>>> - from different processes? >>> I think this should be done in the same way as for Meshes. We >>> discussed the following design: >>> >>> 1. Reading a single file "foo.xml" results in each process reading the >>> entire file but skipping data located on another process as determined >>> by local_range. This is what is implemented now for meshes (followed >>> by communication and mesh partitioning). The difference for vectors >>> would be that no extra communication is necessary. >>> >> OK. >> >>> 2. Reading a set of files "foo*.xml" results in each process reading >>> its portion stored in "foo%d.xml" % p. The File interface then needs >>> to check for the occurence of '*' and figure out the correct file name >>> based on its process number. >>> >> I think that are a number of advantages to having a single .xml that >> points to the 'sub-files'. An obvious advantage is that we won't need to >> distinguish between cases 1 and 2 when reading in a vector. >> >> Garth > > I don't feel strongly about either option, but if we go for the > master-file/sub-file design I think we should do the same for vectors > and meshes. > > The master file could look something like this for vectors: > > <distributed_vector size="1024" num_partitions="16"> > <sub_vector partition="0" file="foo_0.xml" offset="0"/> > <sub_vector partition="1" file="foo_1.xml" offset="64"/> > <sub_vector partition="2" file="foo_2.xml" offset="128"/> > ... > </distributed_vector> >
Looks good, except 'offset' should be 'size', or 'local_size'. Garth > For meshes, we can do this: > > <distributed_mesh num_partitions="16"> > <sub_mesh partition="0" file="foo_0.xml"/> > <sub_vector partition="1" file="foo_1.xml"/> > <sub_vector partition="2" file="foo_2.xml"/> > ... > </distributed_mesh> > > -- > Anders _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
