From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 29E4C4D2EE9; Tue, 9 Jun 2026 19:11:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781032314; cv=none; b=QbPNV1hNVrdSXGvrxAtXA2CTbLlJ0oNsSgfc5Ss5sNhSe20kjdUd7G8g4rTk7BK0LvTnKMeKUD6RBcRNtdUXoBDD0vFd2oBcuSKQOcewFondcAsi1lhh7Nwhkh8gZbrgrbDia7ATHezWKm9rP+/nb5wTtycmMq2i7mVORDYAcdM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781032314; c=relaxed/simple; bh=aC+DAIoXKVhLZjQ6VtxK/CU+nypY/dW+t6e//OC/LfI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ST0t+Q858cGPYXkX5ZwwKifaHaRrMrzyQTK7b9LLUj6NLjqAIfVAq2526cqzTFtZTY4jueeTreY2+JZv4MeKaXXU8pT/b6pUXbpSolppXMgaz/18Yd5WcMkUIDH3nP0iIRUdBTmcZp4iot9gvc73y9sBA4D7AzvXGx6v6pb+4dI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BBqeDFBO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BBqeDFBO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E8E21F00893; Tue, 9 Jun 2026 19:11:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781032313; bh=LG6tMe5IWSj2wlms7qY7Y93GPHV0FPQd/hj6Ivr47HU=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=BBqeDFBO6IhOZgXsVP1UWzizuRgZi3kU7sfun64CmXti2K6oPjtIBK9ig3BdDxI99 cF7sX5GSOB9a6RMswzwGJ7G7wZWyz/OfM3ww7kqrGDbMJUrfhm2MfUAy4dhiIJfUv9 lxKN4uCMP2DKqoRBLiWW+W+lxD3bzRPoS1unHHzrTSIUA5h5UlVsTL+dXBA1j4FZLV rMUy57xguGXz2SWZBBNK+OUjIdOGj04TXu2YFAKrqi0ypCd7uemPexNeQWMWarv446 GXbWEZYV7iPTK5o/ZILzn8GsZmANF8B20sLgQqjMB8ZeqEKOEZdqbn6/zR5YMgJkYr bqqCWK/4xzSTA== From: Andreas Hindborg Date: Tue, 09 Jun 2026 21:09:01 +0200 Subject: [PATCH v2 82/83] block: rnull: add `shared_tag_bitmap` config option Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260609-rnull-v6-19-rc5-send-v2-82-82c7404542e2@kernel.org> References: <20260609-rnull-v6-19-rc5-send-v2-0-82c7404542e2@kernel.org> In-Reply-To: <20260609-rnull-v6-19-rc5-send-v2-0-82c7404542e2@kernel.org> To: "Liam R. Howlett" , Alice Ryhl , Anna-Maria Behnsen , Benno Lossin , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Boqun Feng , Danilo Krummrich , FUJITA Tomonori , Frederic Weisbecker , Gary Guo , Jens Axboe , John Stultz , Lorenzo Stoakes , Lyude Paul , Miguel Ojeda , Stephen Boyd , Thomas Gleixner , Trevor Gross , "Liam R. Howlett" , Boqun Feng , Lorenzo Stoakes Cc: Andreas Hindborg , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rust-for-linux@vger.kernel.org X-Mailer: b4 0.16-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=5599; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=aC+DAIoXKVhLZjQ6VtxK/CU+nypY/dW+t6e//OC/LfI=; b=owEBbQKS/ZANAwAKAfpQKQiqxb3QAcsmYgBqKGT+NlnHQn5rbaLOqNWNJZ4pO68g/2hZz04u7 eduX1XgsBqJAjMEAAEKAB0WIQRXitnI2WZ2JirAaob6UCkIqsW90AUCaihk/gAKCRD6UCkIqsW9 0PeWD/90gWv84QyKgx1/RYvYIvXyS8hP7dIG5obg9kqAuuG0GqZasGqXWQwPi7fElVX7xT3U2jr HPB7ByYGppRrwvyHt6ai6tGJAAY8No0tir/Lf5sW+HIZy4rJmWSid+N9fhnWj0yft0TGKqmMx/v ucDqJO9i3hfO6qGo/0nFAgB2f4ao7DZ66A3Z494exLc3UvYGIbhgo6Ux1GcY8EZvKmD4Sz2mKDq U7Sgv/YbBaacDWVZSopGuy6V3KwESVPjmEUFwVaXxKvgK5enyB+DryohgVsTKzrcZB2Kxi0dIoT 42UzjEo+Kw6pNiADr2FvTSzmGfpdGbJta9bdVt/ehnJPf4RYMiaASV3JkY1W5bhaUtqyU6nsvca YnW0ymLhTvxVkaaUHODoEyhbMYRpPKoDd/VYXcW37a/QATqEYS0NX5O9j8j/H55gpDRt/SiN9qc BsTP/kqQAk3962iTwxTiDEeNfcGbZ/jSszC4svAyMcqMC21DBdq41SrV8fhKOeigFaWuzeilq9U PO6lsfFeREpMMJkPbT8hyElT3qnFzQ4qk7MgfpEp+XqZCqyFqKnISg+ECIm8gwcsEYFD3FNukZk gqKc75NFApUc40oqvG4e76V8QyYJNVoK6Tg38XcH59mRvwQibccjYe/xcrGVJ7MGeTZmzB4Zo9T rtv+TYGXxJnL7zg== X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 Add a configfs attribute and module parameter to enable the `BLK_MQ_F_TAG_HCTX_SHARED` flag for the rnull tag set. When enabled, a tag bitmap is shared across all hardware queues. Signed-off-by: Andreas Hindborg --- drivers/block/rnull/configfs.rs | 5 +++++ drivers/block/rnull/rnull.rs | 12 ++++++++++++ rust/kernel/block/mq/tag_set/flags.rs | 4 ++++ 3 files changed, 21 insertions(+) diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs index 3e054339226c..1bab38c55698 100644 --- a/drivers/block/rnull/configfs.rs +++ b/drivers/block/rnull/configfs.rs @@ -134,6 +134,7 @@ fn make_group( fua: 28, max_sectors: 29, virt_boundary: 30, + shared_tag_bitmap: 31, ], }; @@ -223,6 +224,7 @@ fn make_group( init_hctx_inject, max_sectors: 0, virt_boundary: false, + shared_tag_bitmap: false, }), }), default_groups, @@ -318,6 +320,7 @@ struct DeviceConfigInner { init_hctx_inject: Arc, max_sectors: u32, virt_boundary: bool, + shared_tag_bitmap: bool, } #[vtable] @@ -374,6 +377,7 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result { blocking: guard.blocking, memory_backed: guard.memory_backed, no_sched: guard.no_sched, + shared_tag_bitmap: guard.shared_tag_bitmap, hw_queue_depth: guard.hw_queue_depth, #[cfg(CONFIG_BLK_DEV_RUST_NULL_FAULT_INJECTION)] init_hctx_inject: guard.init_hctx_inject.clone(), @@ -622,3 +626,4 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result { configfs_simple_bool_field!(DeviceConfig, 28, fua); configfs_simple_field!(DeviceConfig, 29, max_sectors, u32); configfs_simple_bool_field!(DeviceConfig, 30, virt_boundary); +configfs_simple_bool_field!(DeviceConfig, 31, shared_tag_bitmap); diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs index 147dc8498c3a..81f9e2d03f31 100644 --- a/drivers/block/rnull/rnull.rs +++ b/drivers/block/rnull/rnull.rs @@ -216,6 +216,10 @@ default: false, description: "Set alignment requirement for IO buffers to be page size.", }, + shared_tag_bitmap: bool { + default: false, + description: "Use shared tag bitmap for all submission queues for blk-mq.", + }, }, } @@ -245,6 +249,7 @@ fn init(_module: &'static ThisModule) -> impl PinInit { let memory_backed = module_parameters::memory_backed.value(); let no_sched = module_parameters::no_sched.value(); let hw_queue_depth = module_parameters::hw_queue_depth.value(); + let shared_tag_bitmap = module_parameters::shared_tag_bitmap.value(); let shared_tag_set = NullBlkDevice::build_tag_set(TagSetOptions { home_node, @@ -258,6 +263,7 @@ fn init(_module: &'static ThisModule) -> impl PinInit { blocking, memory_backed, no_sched, + shared_tag_bitmap, hw_queue_depth, #[cfg(CONFIG_BLK_DEV_RUST_NULL_FAULT_INJECTION)] init_hctx_inject: Arc::pin_init( @@ -300,6 +306,7 @@ fn init(_module: &'static ThisModule) -> impl PinInit { blocking, memory_backed, no_sched, + shared_tag_bitmap, hw_queue_depth, #[cfg(CONFIG_BLK_DEV_RUST_NULL_FAULT_INJECTION)] init_hctx_inject: Arc::pin_init( @@ -404,6 +411,7 @@ struct TagSetOptions { blocking: bool, memory_backed: bool, no_sched: bool, + shared_tag_bitmap: bool, hw_queue_depth: u32, #[cfg(CONFIG_BLK_DEV_RUST_NULL_FAULT_INJECTION)] init_hctx_inject: Arc, @@ -419,6 +427,7 @@ fn build_tag_set(options: TagSetOptions) -> Result>> { blocking, memory_backed, no_sched, + shared_tag_bitmap, hw_queue_depth, #[cfg(CONFIG_BLK_DEV_RUST_NULL_FAULT_INJECTION)] init_hctx_inject, @@ -441,6 +450,9 @@ fn build_tag_set(options: TagSetOptions) -> Result>> { if no_sched { flags |= mq::tag_set::Flag::NoDefaultScheduler; } + if shared_tag_bitmap { + flags |= mq::tag_set::Flag::TagHctxShared; + } let queue_config_guard = queue_config.lock(); let submit_queues = queue_config_guard.submit_queues; diff --git a/rust/kernel/block/mq/tag_set/flags.rs b/rust/kernel/block/mq/tag_set/flags.rs index 2561d7090c49..afc9d31ed998 100644 --- a/rust/kernel/block/mq/tag_set/flags.rs +++ b/rust/kernel/block/mq/tag_set/flags.rs @@ -21,5 +21,9 @@ pub enum Flag { /// Select 'none' during queue registration in case of a single hwq or shared /// hwqs instead of 'mq-deadline'. NoDefaultScheduler = bindings::BLK_MQ_F_NO_SCHED_BY_DEFAULT, + + /// Use shared tag bitmap for all submission queues. + TagHctxShared = bindings::BLK_MQ_F_TAG_HCTX_SHARED, + } } -- 2.51.2