Hi, >So I think we're mostly trying to work out what our API should really >be, whether we should extend the distro functionality vs. going totally >to hints, and if we go to hints what that API should look like, right? probably the distribution needs a function which initializes/sets the internal parameter depending on the string. Maybe another one which fancy writes the parameters to a char buffer.
> I'm down with that. For the record, my concern over strings isn't in > our processing them - its the users having to muck with them - > especially when passing numeric data. I just worry about lots of > mallocing/string copying blech when all you really want to do is set the > stripe size to the variable x. I think extra mallocing is not really necessary only once to generate the string which can be generated with snprintf the string could look like "ioservercount=2;ioservers=node1,node4;dist=simplestripe;dist_stripesize=65536" whereas options without the prefix "dist_" may be processed by code common to all distributions. I do not see the benefit of putting the responsibility of server mapping to the distribution right now (maybe for raid ?). I like outsourced/common processing which is done in the create sm right now. >I personally don't think the environment variable approach is all that >useful for PVFS. I believe this because there are only a *very* limited >number of cases where it would apply cleanly (e.g. pvfs2-cp) that there >isn't another mechanism for doing the same thing (e.g. MPI-IO hints). I >think that MPI-IO hints should have some mechanism along those lines, >and I wouldn't mind discussing that separately, but that's a different >topic. Ok I think its true that it might not be that useful for the common case and that MPI hints should be used. I found it useful for testing and experimenting with PVFS and I think its no big deal if environment processing will not be added to CVS. I will add the functionality fitting to the new hint interface in my branch. I don't think that I actually might be useful for implementing the new hint mechanism because I think you have to revise the code anyway (and it won't be so much work I guess, either), but that is no big deal. Julian _______________________________________________ Pvfs2-developers mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
