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McKenney" , Alexander Viro , Jan Kara , Miguel Ojeda , Boqun Feng , "=?utf-8?q?Bj=C3=B6rn_Roy_Baron?=" , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , Gary Guo , linux-fsdevel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Alice Ryhl Content-Type: text/plain; charset="utf-8" Right now Rust Binder calls synchronize_rcu() more often than is necessary. Most processes do not use epoll at all, so they don't require rcu here. Back in Kangrejos I came up with a way to avoid this. Idea is to move the value that needs rcu to a separate allocation that's easy to kfree_rcu(). We pay the allocation only when the proc uses epoll using an "upgrade" strategy - most processes don't. Signed-off-by: Alice Ryhl --- Changes in v3: - This series was almost entirely rewritten to use a different implementation strategy. By moving the PollCondVar to the process we can avoid the upgrade logic entirely. - Link to v2: https://lore.kernel.org/r/20260213-upgrade-poll-v2-0-984a0fb184fb@google.com Changes in v2: - Change how Rust Binder handles the lock class key. - Rebase. - Link to v1: https://lore.kernel.org/r/20260117-upgrade-poll-v1-0-179437b7bd49@google.com --- Alice Ryhl (2): rust: poll: use kfree_rcu() for PollCondVar rust_binder: move (e)poll wait queue to Process drivers/android/binder/process.rs | 51 +++++++++++++++++------ drivers/android/binder/thread.rs | 78 +++++++++++++++++------------------ drivers/android/binder/transaction.rs | 4 ++ rust/kernel/sync/poll.rs | 73 +++++++++++++++++++++++++++++++- 4 files changed, 154 insertions(+), 52 deletions(-) --- base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731 change-id: 20260117-upgrade-poll-37ee2a7a79dd Best regards, -- Alice Ryhl