From nobody Mon Feb 9 18:01:39 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 230BA21B9FC; Mon, 31 Mar 2025 21:03:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743454996; cv=none; b=OCp6EDwQVkML5PI+ag+PDiJyJsDGHAbctq3fRQNCjovqarfy23MkZ0jBtdEDcm3rtGMhSWVJ/oGh55OLrPaSj/5WWnlXR6Pd6V3zfx4fwbopf2dAgIMGG8gpG8WIKVxoYmkoQSwcqfv35G3CjzSdmUom2IPJOXKrHmWX0TnBX3o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743454996; c=relaxed/simple; bh=95yGZppaZZxoJNnNv8N0HfRV+XlPNqEDRvJVFtromRk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=SxRjtwNjsgM44MI4Lb0JWdPJj2L7gvwKAWzXsAGsM8aGH0hxIoMBc3jkbnUPss9sitGuqG9AXAqgpmMT7A3kpfSC4VMWpDcJVC39P3hmZbO/X7i8MDM+9JMA1Ykm7J7GbOdMEOMBxGwAIp0Flc3H9lVZzP0O4vPfHlnBDgX3Aiw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CRea347K; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CRea347K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C933EC4CEF3; Mon, 31 Mar 2025 21:03:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743454995; bh=95yGZppaZZxoJNnNv8N0HfRV+XlPNqEDRvJVFtromRk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CRea347KjhdlzVfvJEH/NfNFmqmypO9mjv04ULyxp16D/aiF7o4KlYzrWay6hNJdZ jpdbRR1AtDFj2qqwRovT6wSW31XsJMGepmtkfid5UH8MiKx3zUN5nsgUnJNkZmJI9G bzH47j/Nz2fygb6yfpCoG0UyT2j7ICKW2//EZ/E9l0Yk4iBcZ7hsLzWH/zVv0zKPoL CslapDzVz4v5jvRUBsWV7rEkjqIJ9X2hSkx13451GmEzaXOF+4gJ6N4r8A1ZU671mz vbzho6kqCznqC5ueMrrtJUJTib7cnw22VmzgMMnbwm2scvalaTiB13/UXX6U8srzzU eB0twgqBHIoWg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 33F59CE12A6; Mon, 31 Mar 2025 14:03:15 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org, Joel Fernandes Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH v2 07/12] rcutorture: Comment invocations of tick_dep_set_task() Date: Mon, 31 Mar 2025 14:03:09 -0700 Message-Id: <20250331210314.590622-7-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: 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" The rcu_torture_reader() and rcu_torture_fwd_prog_cr() functions run CPU-bound for extended periods of time (tens or even hundreds of milliseconds), so they invoke tick_dep_set_task() and tick_dep_clear_task() to ensure that the scheduling-clock tick helps move grace periods forward. So why doesn't rcu_torture_fwd_prog_nr() also invoke tick_dep_set_task() and tick_dep_clear_task()? Because the point of this function is to test RCU's ability to (eventually) force grace periods forward even when the tick has been disabled during long CPU-bound kernel execution. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 7eccc74e60a7f..ea40f3ad32dc2 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2410,7 +2410,7 @@ rcu_torture_reader(void *arg) set_user_nice(current, MAX_NICE); if (irqreader && cur_ops->irq_capable) timer_setup_on_stack(&t, rcu_torture_timer, 0); - tick_dep_set_task(current, TICK_DEP_BIT_RCU); + tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. do { if (irqreader && cur_ops->irq_capable) { if (!timer_pending(&t)) @@ -3260,7 +3260,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *r= fp) cver =3D READ_ONCE(rcu_torture_current_version); gps =3D cur_ops->get_gp_seq(); rfp->rcu_launder_gp_seq_start =3D gps; - tick_dep_set_task(current, TICK_DEP_BIT_RCU); + tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. while (time_before(jiffies, stopat) && !shutdown_time_arrived() && !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { --=20 2.40.1