From: Boqun Feng <boqun.feng@gmail.com>
To: Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>
Cc: "Will Deacon" <will@kernel.org>,
"Waiman Long" <longman@redhat.com>,
linux-kernel@vger.kernel.org, "Alice Ryhl" <aliceryhl@google.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Andreas Hindborg" <a.hindborg@kernel.org>,
"Trevor Gross" <tmgross@umich.edu>,
"Mitchell Levy" <levymitchell0@gmail.com>,
"Danilo Krummrich" <dakr@kernel.org>,
"Christian Brauner" <brauner@kernel.org>,
"Martin Rodriguez Reboredo" <yakoyoku@gmail.com>,
rust-for-linux@vger.kernel.org (open list:RUST)
Subject: [PATCH locking 09/11] rust: sync: condvar: Add wait_interruptible_freezable()
Date: Fri, 7 Mar 2025 15:26:59 -0800 [thread overview]
Message-ID: <20250307232717.1759087-10-boqun.feng@gmail.com> (raw)
In-Reply-To: <20250307232717.1759087-1-boqun.feng@gmail.com>
From: Alice Ryhl <aliceryhl@google.com>
To support waiting for a `CondVar` as a freezable process, add a
wait_interruptible_freezable() function.
Binder needs this function in the appropriate places to freeze a process
where some of its threads are blocked on the Binder driver.
[Boqun: Capitalize the title, reword the commit log and rephrase the
function doc comment with the impersonal style to align with rest of the
file]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250204-condvar-freeze-v2-1-804483096260@google.com
---
rust/kernel/sync/condvar.rs | 23 ++++++++++++++++++++++-
rust/kernel/task.rs | 2 ++
2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index 7df565038d7d..5c1e546a26c3 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -11,7 +11,9 @@
init::PinInit,
pin_init,
str::CStr,
- task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE},
+ task::{
+ MAX_SCHEDULE_TIMEOUT, TASK_FREEZABLE, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE,
+ },
time::Jiffies,
types::Opaque,
};
@@ -159,6 +161,25 @@ pub fn wait_interruptible<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T,
crate::current!().signal_pending()
}
+ /// Releases the lock and waits for a notification in interruptible and freezable mode.
+ ///
+ /// The process is allowed to be frozen during this sleep. No lock should be held when calling
+ /// this function, and there is a lockdep assertion for this. Freezing a task that holds a lock
+ /// can trivially deadlock vs another task that needs that lock to complete before it too can
+ /// hit freezable.
+ #[must_use = "wait_interruptible_freezable returns if a signal is pending, so the caller must check the return value"]
+ pub fn wait_interruptible_freezable<T: ?Sized, B: Backend>(
+ &self,
+ guard: &mut Guard<'_, T, B>,
+ ) -> bool {
+ self.wait_internal(
+ TASK_INTERRUPTIBLE | TASK_FREEZABLE,
+ guard,
+ MAX_SCHEDULE_TIMEOUT,
+ );
+ crate::current!().signal_pending()
+ }
+
/// Releases the lock and waits for a notification in interruptible mode.
///
/// Atomically releases the given lock (whose ownership is proven by the guard) and puts the
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 07bc22a7645c..ea43a3b8d9c5 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -23,6 +23,8 @@
pub const TASK_INTERRUPTIBLE: c_int = bindings::TASK_INTERRUPTIBLE as c_int;
/// Bitmask for tasks that are sleeping in an uninterruptible state.
pub const TASK_UNINTERRUPTIBLE: c_int = bindings::TASK_UNINTERRUPTIBLE as c_int;
+/// Bitmask for tasks that are sleeping in a freezable state.
+pub const TASK_FREEZABLE: c_int = bindings::TASK_FREEZABLE as c_int;
/// Convenience constant for waking up tasks regardless of whether they are in interruptible or
/// uninterruptible sleep.
pub const TASK_NORMAL: c_uint = bindings::TASK_NORMAL as c_uint;
--
2.47.1
next prev parent reply other threads:[~2025-03-07 23:29 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-26 4:12 [GIT PULL] LOCKDEP and Rust locking changes for v6.15 Boqun Feng
2025-02-28 18:57 ` Boqun Feng
2025-03-03 16:52 ` Waiman Long
2025-03-03 18:42 ` Peter Zijlstra
2025-03-07 23:26 ` [PATCH locking 00/11] " Boqun Feng
2025-03-07 23:26 ` [PATCH locking 01/11] locking/rtmutex: Use struct keyword in kernel-doc comment Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] locking/rtmutex: Use the 'struct' " tip-bot2 for Randy Dunlap
2025-03-07 23:26 ` [PATCH locking 02/11] locking/semaphore: Use wake_q to wake up processes outside lock critical section Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 03/11] locking/lock_events: Add locking events for rtmutex slow paths Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 04/11] locking/lock_events: Add locking events for lockdep Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 05/11] locking/lockdep: Disable KASAN instrumentation of lockdep.c Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 06/11] locking/lockdep: Add kasan_check_byte() check in lock_acquire() Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Waiman Long
2025-03-07 23:26 ` [PATCH locking 07/11] rust: sync: Add accessor for the lock behind a given guard Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Alice Ryhl
2025-03-07 23:26 ` [PATCH locking 08/11] rust: sync: lock: Add an example for Guard::lock_ref() Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] rust: sync: lock: Add an example for Guard:: Lock_ref() tip-bot2 for Boqun Feng
2025-03-07 23:26 ` Boqun Feng [this message]
2025-03-08 0:08 ` [tip: locking/core] rust: sync: condvar: Add wait_interruptible_freezable() tip-bot2 for Alice Ryhl
2025-03-07 23:27 ` [PATCH locking 10/11] rust: lockdep: Remove support for dynamically allocated LockClassKeys Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Mitchell Levy
2025-03-07 23:27 ` [PATCH locking 11/11] rust: lockdep: Use Pin for all LockClassKey usages Boqun Feng
2025-03-08 0:08 ` [tip: locking/core] " tip-bot2 for Mitchell Levy
2025-03-08 0:01 ` [PATCH locking 00/11] LOCKDEP and Rust locking changes for v6.15 Ingo Molnar
2025-03-08 0:04 ` Boqun Feng
2025-03-08 0:11 ` Ingo Molnar
2025-03-08 0:11 ` Boqun Feng
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