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[103.168.172.200]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7c3e54ff7a5sm302875285a.82.2025.03.07.15.29.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Mar 2025 15:29:16 -0800 (PST) Received: from phl-compute-08.internal (phl-compute-08.phl.internal [10.202.2.48]) by mailfauth.phl.internal (Postfix) with ESMTP id 00717120006A; Fri, 7 Mar 2025 18:29:16 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-08.internal (MEProxy); Fri, 07 Mar 2025 18:29:16 -0500 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduudduleelucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggv pdfurfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpih gvnhhtshculddquddttddmnecujfgurhephffvvefufffkofgjfhgggfestdekredtredt tdenucfhrhhomhepuehoqhhunhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrih hlrdgtohhmqeenucggtffrrghtthgvrhhnpefghfffvefhhfdvgfejgfekvdelgfekgeev ueehlefhiedvgeffjefgteeugfehieenucffohhmrghinhepkhgvrhhnvghlrdhorhhgne cuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepsghoqhhu nhdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqieelvdeghedtieegqdduje ejkeehheehvddqsghoqhhunhdrfhgvnhhgpeepghhmrghilhdrtghomhesfhhigihmvgdr nhgrmhgvpdhnsggprhgtphhtthhopeduledpmhhouggvpehsmhhtphhouhhtpdhrtghpth htohepmhhinhhgoheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepphgvthgvrhiisehi nhhfrhgruggvrggurdhorhhgpdhrtghpthhtohepfihilhhlsehkvghrnhgvlhdrohhrgh dprhgtphhtthhopehlohhnghhmrghnsehrvgguhhgrthdrtghomhdprhgtphhtthhopehl ihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhope grlhhitggvrhihhhhlsehgohhoghhlvgdrtghomhdprhgtphhtthhopegsohhquhhnrdhf vghnghesghhmrghilhdrtghomhdprhgtphhtthhopehojhgvuggrsehkvghrnhgvlhdroh hrghdprhgtphhtthhopegrlhgvgidrghgrhihnohhrsehgmhgrihhlrdgtohhm X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 7 Mar 2025 18:29:15 -0500 (EST) From: Boqun Feng To: Ingo Molnar , Peter Zijlstra Cc: Will Deacon , Waiman Long , linux-kernel@vger.kernel.org, Alice Ryhl , Boqun Feng , Miguel Ojeda , Alex Gaynor , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Andreas Hindborg , Trevor Gross , Mitchell Levy , Danilo Krummrich , Christian Brauner , Martin Rodriguez Reboredo , 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 Message-ID: <20250307232717.1759087-10-boqun.feng@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250307232717.1759087-1-boqun.feng@gmail.com> References: <20250307232717.1759087-1-boqun.feng@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Alice Ryhl 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 Signed-off-by: Boqun Feng Link: https://lore.kernel.org/r/20250204-condvar-freeze-v2-1-804483096260@g= oogle.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_UNI= NTERRUPTIBLE}, + task::{ + MAX_SCHEDULE_TIMEOUT, TASK_FREEZABLE, TASK_INTERRUPTIBLE, TASK_NOR= MAL, TASK_UNINTERRUPTIBLE, + }, time::Jiffies, types::Opaque, }; @@ -159,6 +161,25 @@ pub fn wait_interruptible(&self= , guard: &mut Guard<'_, T, crate::current!().signal_pending() } =20 + /// Releases the lock and waits for a notification in interruptible an= d freezable mode. + /// + /// The process is allowed to be frozen during this sleep. No lock sho= uld 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 com= plete before it too can + /// hit freezable. + #[must_use =3D "wait_interruptible_freezable returns if a signal is pe= nding, so the caller must check the return value"] + pub fn wait_interruptible_freezable( + &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 mo= de. /// /// Atomically releases the given lock (whose ownership is proven by t= he 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 =3D bindings::TASK_INTERRUPTIBLE as c_= int; /// Bitmask for tasks that are sleeping in an uninterruptible state. pub const TASK_UNINTERRUPTIBLE: c_int =3D bindings::TASK_UNINTERRUPTIBLE a= s c_int; +/// Bitmask for tasks that are sleeping in a freezable state. +pub const TASK_FREEZABLE: c_int =3D bindings::TASK_FREEZABLE as c_int; /// Convenience constant for waking up tasks regardless of whether they ar= e in interruptible or /// uninterruptible sleep. pub const TASK_NORMAL: c_uint =3D bindings::TASK_NORMAL as c_uint; --=20 2.47.1