#994: read EOS table on single process the broadcast -----------------------------------+---------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: new Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Keywords: EOS_Omni | -----------------------------------+---------------------------------------- this patch limits IO at startup by having a single process (specifiable via a parameter) read the table and the MPI broadcast the data to the others.
#994: read EOS table on single process the broadcast ------------------------------------+--------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: review Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: EOS_Omni ------------------------------------+--------------------------------------- Changes (by rhaas):
* status: new => review
#994: read EOS table on single process the broadcast ------------------------------------+--------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: review Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: EOS_Omni ------------------------------------+---------------------------------------
Comment (by eschnett):
I do not understand this patch.
- Where is the if statement that prevents the HDF5 calls if !do_IO? - sizeof *(VAR) is probably 8 (for double), not the size of the whole table - Ideally, the MPI_Bcast would use MPI_DOUBLE, not MPI_BYTE - I would rename "read_table_on_this_process" to "reader_process", since the former sounds like a boolean flag
#994: read EOS table on single process the broadcast ------------------------------------+--------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: review Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: EOS_Omni ------------------------------------+---------------------------------------
Comment (by rhaas):
The patch contains at least one bug.
* the statement that prevents HDF5 calls is in HDF5_ERROR which wraps all HDF5 calls * this is clearly a bug. I'll amend * That would require several macros since right now the same macro is used for all HDF5 types and I did not want to make a mapping from MPI to HDF5 types * the rename sounds fine, the current name is awkward
#994: read EOS table on single process the broadcast ------------------------------------+--------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: review Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: EOS_Omni ------------------------------------+---------------------------------------
Comment (by rhaas):
I corrected the bug Erik pointed out. I left MPI_Bcast using MPI_BYTE since the alternative is to have a MPI_INT and MPI_DOUBLE version as well as having to worry (even more) about MPI_DOUBLE != H5T_NATIVE_DOULBE != CCTK_REAL. Transferring the data as an undifferentiated stream of bytes should be fine unless we are on a heterogeneous cluster (at which point I will gladly rewrite this routine once the rest of Cactus works :-) ).
#994: read EOS table on single process the broadcast ------------------------------------+--------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: reviewed_ok Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: EOS_Omni ------------------------------------+--------------------------------------- Changes (by eschnett):
* status: review => reviewed_ok
Comment:
Please rename and update the comment for HDF5_ERROR, since it not only checks for errors. It also contains the logic deciding whether to call HDF5 at all.
Please apply.
#994: read EOS table on single process the broadcast ------------------------------------+--------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: closed Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: fixed | Keywords: EOS_Omni ------------------------------------+--------------------------------------- Changes (by rhaas):
* status: reviewed_ok => closed * resolution: => fixed
Comment:
applied as r65 of EOS_Omni.
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