Build a Learning Habit
Download Class Central's free printable study calendar
Download for Free
Learn about Android's migration from the ashmem (anonymous shared memory) allocator to the upstream Linux kernel's memfd facility in this 15-minute conference talk from the Linux Plumbers Conference. Discover how Android currently relies on ashmem to allocate anonymous buffers for fast inter-process sharing via file descriptors, built on top of Linux's shmem subsystem. Understand the key drawbacks of ashmem, including its status as Android-specific technical debt outside the upstream kernel and lack of upstream test coverage. Explore Android's strategic approach to seamlessly transition from ashmem to the similar but upstream-supported memfd facility. Examine the technical challenges and solutions involved in this migration, including maintaining backward compatibility with older applications and devices, and implementing SELinux support for fine-grained memfd access control. Gain insights into the forward-facing work required to complete this transition while preserving the fast memory sharing capabilities that Android applications depend on.
