Re: [openib-general] MTHCA features
roland James It is my understanding that the current MTHCA driver does roland James not support InfiniBand memory windows or memory roland James registration using virtual addresses. roland roland James Is this information correct? If so, when will these roland James features be supported? roland roland Well, memory registration is pretty complete. By design, we only roland support memory registration with physical addresses for kernel roland consumers even at the verbs API level (ie there are no mthca-specific roland limitations). In the kernel, registration by virtual address is not roland very useful. For userspace verbs, only registration by virtual roland address is supported for obvious reasons. roland roland Memory windows are not implemented for mthca. It wouldn't be a lot of roland work for someone with access to Mellanox documentation to implement roland them, but they're not particularly useful due to their performance roland characteristics. Is anyone on this list working on memory window support? I ask because the DAT API contains interfaces that allow users to interact with memory windows. ___ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] MTHCA features
James I ask because the DAT API contains interfaces that allow James users to interact with memory windows. Are there any real applications that use those interfaces? Thanks, Roland ___ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] MTHCA features
Or By performance characteristics do you mean the extra Or overhead to generate another rkey for the already registered Or address range (and also to create/free the mw)? No, I mean the performance cost of binding/unbinding the MW. - R. ___ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] MTHCA features
NFS/RDMA doesn't require memory windows but it will make use of them if they are available. -james On Tue, 1 Mar 2005, Roland Dreier wrote: James I ask because the DAT API contains interfaces that allow James users to interact with memory windows. Are there any real applications that use those interfaces? Thanks, Roland ___ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
RE: [openib-general] MTHCA features
Roland Memory windows are not implemented for mthca. It wouldn't be a lot of Roland work for someone with access to Mellanox documentation to implement Roland them, but they're not particularly useful due to their performance characteristics. By performance characteristics do you mean the extra overhead to generate another rkey for the already registered address range (and also to create/free the mw)? I guess an app that registers huge portions of memory in batch/startup time can also doing mw-ing in this time and not in the fast flow. It then have at hand pool of rkeys which it can use and recycle at run time. Or. ___ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
