> On Tue, Feb 02, 2021 at 12:05:36PM -0500, Peter Xu wrote: > >> > Gal, you could also MADV_DONTFORK this range if you are explicitly >> > allocating them via special mmap. >> >> Yeah I wanted to mention this one too but I just forgot when reply: the issue >> thread previously pasted smells like some people would like to drop >> MADV_DONTFORK, but if it's able to still be applied I don't know why >> not.. > > I want to drop the MADV_DONTFORK for dynamic data memory allocated by > the application layers (eg with malloc) without knowledge of how they > will be used. > > This case is a buffer internal to the communication system that we > know at allocation time how it will be used; so an explicit, > deliberate, MADV_DONTFORK is fine We are referring to libfabric's bounce buffers, correct? Libfabric could be considered as the "app" here, it's not clear why these buffers should be DONTFORK'd before ibv_reg_mr() but others don't. Anyway, it should be simple enough to madvise them after allocation, although I think it's part of libfabric's generic code (which isn't necessarily used on top of rdma-core). I'll take this discussion with the libfabric guys. Thanks Peter and Jason.
