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 8EAED380FFB; Sat, 19 Sep 2026 00:01:04 +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=1789776066; cv=none; b=m2EHjFSJW868zkFij1bL/cq8mqBJHngaDx+LGg0mvNIp03BdLP2b22t55PTp4E6RVD8+98MA9BIZVAvbFQEOA8Sdzp0ewvHw7IzpwlqPM1HFA+yub4ZFmqPbvRtwtVg1PsW9RR6/lOzibv66zpEzvFOTBfT52nmJlV+61+uDwXw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789776066; c=relaxed/simple; bh=emhGjryoKAzeixDJ+IrrZwVL7nh8IOIJ6cHVlsM6gNE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eDHFz1NdXj1niF6R4PlAIuuQeC2pW67Q778X1EUguChSung+RVkTg0Oj+f8C3/fzueHQd4QdyuznBML52eDgFaFOB49tLf+RJdo8lZd0DG+a0VaOYuhEuipedbCUlw1gZtP5RmXlXV+MjlUCWKtaBVIiMoHFfYeoos3rFyZ0cvI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bxrXohui; 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="bxrXohui" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C55A1F00923; Sat, 19 Sep 2026 00:01:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789776060; bh=3yJCQ8Pquwx+ZNXNfkooAaUAiyLSRGujHC/iL97Z0b8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bxrXohuic1X8pxbpUlRPtmPNy4MBeRhfI8ebH/thqXFg7CeQjgEAIF0KgWRWHuDMa 3O1dWWD9Th7HuzHKhA/+gwH2wK379C1zWg0wjhBPicYrhh6S2Wa/cyJvZHDEQyaSYp ChxyQrKsiXyw9AjyVehac9+4bzAKXUxFdfHMYxxg4kawVRScB8i3OmcEufrqSNtcVl gNzrwKqEf7JM4Ct6FMt5G6ZqYW62vNTIMPm5t5QvZ1V1kYdoMvJXacRVrebjlm2M4/ 8aaB6svxV6M+jmojzF9GU5sctliHwlNaa8PTx60nMavGHN5/hA1N/qlZ82c6M0N+nl JMxwV49wfVTuQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 7D536CE0E63; Fri, 18 Sep 2026 17:00:59 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org, linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, Mathieu Desnoyers , Boqun Feng , Steven Rostedt , lkmm@lists.linux.dev, Zqiang , Wang Lian , Kunwu Chan , Bradley Morgan , "Paul E. McKenney" Subject: [PATCH 18/28] doc: Add hazptrtorture module parameters Date: Fri, 18 Sep 2026 17:00:46 -0700 Message-Id: <20260919000056.3132131-18-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: 8bit Add the hazard-pointer-torture module parameters to kernel-parameters.txt. Signed-off-by: Paul E. McKenney Cc: Boqun Feng Cc: Mathieu Desnoyers Cc: Cc: --- .../admin-guide/kernel-parameters.txt | 96 +++++++++++++++++++ 1 file changed, 96 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 68647ff4bdd2..e93768fd5c55 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1964,6 +1964,102 @@ Kernel parameters for 64-bit NUMA, off otherwise. Format: 0 | 1 (for off | on) + hazptrtorture.defer_modulus= [KNL] + Defer release of the hazard pointer on average + one out of the specified number of times. Zero + disables. Negative one defaults to 1,000 times + nr_cpu_ids, unless hazptr.kthread_do_pending_ms is + equal to zero, in which case it instead defaults + to zero (disabled). + + hazptrtorture.irq_acquire= [KNL] + Acquire hazard pointers from an irq handler on average + one out of the specified number of times. Zero + disables. Negative one defaults to 1,000 times + nr_cpu_ids. + + hazptrtorture.irq_release= [KNL] + Release hazard pointers from an irq handler on average + one out of the specified number of times. Zero + disables. Negative one defaults to 1,000 times + nr_cpu_ids. + + hazptrtorture.kthread_do_pending_ms= [KNL] + Interval between cleanup of pending (deferred) + hazard-pointer releases in milliseconds. + Zero disables. Negative one defaults to three + milliseconds, unless hazptr.kthread_do_pending_ms + is equal to zero, in which case it instead + defaults to zero (disabled). + + hazptrtorture.nreaders= [KNL] + Number of hazard-pointer reader kthreads, each + of which repeatedly acquires and releases hazard + pointers. If the value is zero, one reader + is spawned. If the value is less than zero, + the absolute value is multiplied by the number + of online CPUs at initialization time. + + hazptrtorture.nwriters= [KNL] + Controls whether or not there is a writer. + There is at most one writer, so this value must + be zero or one. + + hazptrtorture.onoff_holdoff= [KNL] + Set time (s) after boot for CPU-hotplug testing. + + hazptrtorture.onoff_interval= [KNL] + Set time (jiffies) between CPU-hotplug operations, + or zero to disable CPU-hotplug testing. + + hazptrtorture.preempt_duration= [KNL] + Set duration (in milliseconds) of preemptions + by a high-priority FIFO real-time task. Set to + zero (the default) to disable. The CPUs to + preempt are selected randomly from the set that + are online at a given point in time. Races with + CPUs going offline are ignored, with that attempt + at preemption skipped. + + hazptrtorture.preempt_interval= [KNL] + Set interval (in milliseconds, defaulting to one + second) between preemptions by a high-priority + FIFO real-time task. This delay is mediated + by an hrtimer and is further fuzzed to avoid + inadvertent synchronizations. + + hazptrtorture.reader_sleep_us= [KNL] + Set occassional read-side sleep time in + microseconds, defaulting to zero for disabled. + + hazptrtorture.shuffle_interval= [KNL] + Set task-shuffle interval (seconds). Shuffling + tasks allows some CPUs to go into dyntick-idle + mode during the hazptrtorture test. + + hazptrtorture.shutdown_secs= [KNL] + Set time (s) after boot system shutdown. This + is useful for hands-off automated testing. + + hazptrtorture.stat_interval= [KNL] + Time (s) between statistics printk()s. + + hazptrtorture.stutter= [KNL] + Time (s) to stutter testing, for example, + specifying three seconds (the default) causes + the test to run for three seconds, wait + for five seconds, and so on. This tests the + hazard-pointers primitives' ability to transition + abruptly to and from idle. Setting this to zero + disables stuttering. + + hazptrtorture.torture_type= [KNL] + Specify the hazard-pointers implementation + to test. + + hazptrtorture.verbose= [KNL] + Enable additional printk() statements. + hd= [EIDE] (E)IDE hard drive subsystem geometry Format: ,, -- 2.40.1