> On Thu, Oct 08, 2020 at 05:45:31PM +0000, Hefty, Sean wrote: > > > > There have been extensive discussions on github around the MR cache, > > > > deadlocks, libibverbs madvise tracking, and fork. The current > > > > direction is to only enable the MR cache when fork is disabled. > > > > This was done to work-around internal libibverbs tracking. But I > > > > suspect that bypassing that tracking (which is possible) can still > > > > lead to issues when registrations are made through the MR cache. > > > > > > MADV_DONTFORK will be obsolete starting in kernel v5.9 > > > > > > If you can test and confirm that everything works without it then we > > > can detect and disable ibv_fork_init on new kernels. > > > > Interesting. What will the behavior be for registered regions when fork is > > called? > > They are copied into the fork. > > > My concern is that the registrations are made and maintained without > > the application being aware. Will cached registrations need to be > > released when fork is invoked, or is there some other mechanism > > coming into play now? > > MRs continue to reliably point to memory owned in the parent > process. > > The child process will be unable to use any MRs or verbs objects, just > like today.
Thanks - I think this means that fork becomes a non-issue. - Sean _______________________________________________ ofiwg mailing list [email protected] https://lists.openfabrics.org/mailman/listinfo/ofiwg
