* Matthieu Dorier <[email protected]> [2013-04-30 17:32:41]:

If I were to implement an ADIO interface to a file system in mpich3, would I have to implement optimizations like two-phase I/O myself or are these optimizations implemented outside ADIO, independently of the file system?

Hi Matthieu, The ADIO interface enables a filesystem driver to override this functionality, but typically it is 'inherited' by using the _generic_ variants. For example, for BGL: struct ADIOI_Fns_struct ADIO_BGL_operations = { ADIOI_BGL_Open, /* Open */ ADIOI_GEN_OpenColl, /* Collective open */ ADIOI_BGL_ReadContig, /* ReadContig */ ADIOI_BGL_WriteContig, /* WriteContig */ #if BGL_OPTIM_STEP1_2 ADIOI_BGL_ReadStridedColl, /* ReadStridedColl */ ADIOI_BGL_WriteStridedColl, /* WriteStridedColl */ #else ADIOI_GEN_ReadStridedColl, /* ReadStridedColl */ ADIOI_GEN_WriteStridedColl, /* WriteStridedColl */ #endif ADIOI_GEN_SeekIndividual, /* SeekIndividual */ ADIOI_BGL_Fcntl, /* Fcntl */ #if BGL_OPTIM_STEP1_1 ADIOI_BGL_SetInfo, /* SetInfo */ #else ADIOI_GEN_SetInfo, /* SetInfo */ #endif ADIOI_BGL_ReadStrided, /* ReadStrided */ ADIOI_BGL_WriteStrided, /* WriteStrided */ ADIOI_BGL_Close, /* Close */ #ifdef ROMIO_HAVE_WORKING_AIO #warning Consider BG support for NFS before enabling this. ADIOI_GEN_IreadContig, /* IreadContig */ ADIOI_GEN_IwriteContig, /* IwriteContig */ #else ADIOI_FAKE_IreadContig, /* IreadContig */ ADIOI_FAKE_IwriteContig, /* IwriteContig */ #endif ADIOI_GEN_IODone, /* ReadDone */ ADIOI_GEN_IODone, /* WriteDone */ ADIOI_GEN_IOComplete, /* ReadComplete */ ADIOI_GEN_IOComplete, /* WriteComplete */ ADIOI_GEN_IreadStrided, /* IreadStrided */ ADIOI_GEN_IwriteStrided, /* IwriteStrided */ ADIOI_BGL_Flush, /* Flush */ ADIOI_GEN_Resize, /* Resize */ ADIOI_GEN_Delete, /* Delete */ ADIOI_GEN_Feature, /* Features */ }; All of the _GEN_ functions are ADIO independent implementations. Hope this helps, Dries