Hello Alexander, > as I see, current interface of libc alloc() assume that all memory > stored inside is committed (has been called _ds_pool.expand()), so, I > can’t reserve memory and populate it by demand naturally, without > libc alloc changes? For this reason, I wrote in my previous email:
"This feature would work independently from the 'Libc::Mem_alloc'. I think that the use of 'Libc::Mem_alloc' by 'mmap' is not the right way to go when taking mmap beyond it current scope." > By the way, I see a couple of references in genode docs to the way to > "use managed dataspace" and "populate it by phys memory by demand", > while no references to code samples provided? How I can reserve > virtual memory range in component without backend storage, in what > allocator? A high-level description is provided by the Genode-Foundations book: https://genode.org/documentation/genode-foundations/20.05/architecture/Core_-_the_root_of_the_component_tree.html#Region-map_management__RM_ You may find the use of the RM service by the JVM instructive: https://github.com/genodelabs/genode-world/blob/master/src/app/jdk/lib/jvm/os_genode.cpp#L4325 For further use cases, consider grepping the source tree for the corresponding header: cd genode/repos grep -r "\<rm_session/connection" * > What is a difference between them (except difference in DS_SUB_OFFSET > vs local_attach_addr)? More specifically, between returned addresses > from sub_rm.attach_at() and env.rm().attach_at()? Whereas 'env.rm().attach_at' refers to the virtual address space of the component, 'sub_rm.attach_at' refers to the layout of the managed dataspace created via the RM service. The address of the former is a virtual address, the address of the latter is an offset relative to the beginning of the managed dataspace. > otherwise how this alloc will take memory from it? By allocating RAM dataspaces directly via 'env.ram().alloc' and attaching it to an offset within the managed dataspace. Cheers Norman -- Dr.-Ing. Norman Feske Genode Labs https://www.genode-labs.com · https://genode.org Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth _______________________________________________ Genode users mailing list users@lists.genode.org https://lists.genode.org/listinfo/users
