On Wed, 7 Nov 2018 20:15:36 -0800 "Joel Fernandes (Google)" joel@joelfernandes.org wrote:
Android uses ashmem for sharing memory regions. We are looking forward to migrating all usecases of ashmem to memfd so that we can possibly remove the ashmem driver in the future from staging while also benefiting from using memfd and contributing to it. Note staging drivers are also not ABI and generally can be removed at anytime.
One of the main usecases Android has is the ability to create a region and mmap it as writeable, then add protection against making any "future" writes while keeping the existing already mmap'ed writeable-region active. This allows us to implement a usecase where receivers of the shared memory buffer can get a read-only view, while the sender continues to write to the buffer. See CursorWindow documentation in Android for more details: https://developer.android.com/reference/android/database/CursorWindow
It appears that the memfd_create and fcntl manpages will require updating. Please attend to this at the appropriate time?
Actually, it would help the review process if those updates were available now.