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 E5EAC23D283; Thu, 16 Jul 2026 00:18:14 +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=1784161096; cv=none; b=m+Igw28ipJDHbxgg6ngILIXj4nA+DbgqPpSe2suBrMcVjBU29bLs7lPpo8OflnnIjjjwlF9adQnCJcW/BCWBoKil/1bJDbetQzecZWHVtm5hp57/uh+xDxvG7o7Kt07gKJfuSa+ngujZxidRf7UDkBF+seMPSKKMa8kFU2HXLgM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784161096; c=relaxed/simple; bh=gpQurLnFPrnkDNe+MWnj+a7OVfK1lfa352oLOHf8xQw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=PXXQReZiDIfWJvm8s2swGK7rgec+Zla8T0ERQ0QzA3P+6vnUQkzSuzcsvrVmbj0gqsmkpDA3RIQW5X/8h93T2iAnhh7xUvzSUmwm5SGWuyw32FifA8Ou1sA9PueaH1apkoApydtreFHmBtqW1vOS2TLVZUR2SCIFYSe3kla8iw0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DLPtPVIj; 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="DLPtPVIj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9A4B1F00ACA; Thu, 16 Jul 2026 00:18:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784161091; bh=Tk/d40pMOZOxOEG/n4oOtTc7jUK/Df01qF5T3EGToyY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=DLPtPVIj2ZbrlkywyeGSZfEQGXe3GTMlgQZm71TqX2bclYUyPsyYX9c1uVxEWseOf Q819E0GrO3jc+6DRFgXSYGDG/w8VndAQb13qLlsyTVgGtVhokX8cgwC6Njzeoos3ue PQ8PFtqa/K1X68PZcENkTgRHIIyk1FzOUoR0lrnT9Mft+O4RfRZ82TPw87D4fnw1A6 skI7qDC05kdO3oR3ATOrZokJUO8c0tTmgNb4SwKb+FqL6Ef4AX4twbjIeJFoBz8bjq QeIW8GXpOFBylUn4oV9XnCxZ8U+Z93PEEE1eSupDnWi6eNDA9UJfwwDjCaYeO2+wGt cYX96dM5k7D1g== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 4F2E6CE0F71; Wed, 15 Jul 2026 17:18:11 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH RFC v2 18/24] doc: Add hazptrtorture module parameters Date: Wed, 15 Jul 2026 17:18:03 -0700 Message-Id: <20260716001809.11084-18-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <23e34c2e-67fd-45da-b130-e70a131a59ea@paulmck-laptop> References: <23e34c2e-67fd-45da-b130-e70a131a59ea@paulmck-laptop> Precedence: bulk X-Mailing-List: rcu@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 --- .../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 b5493a7f8f2281..7977ce806a2647 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1951,6 +1951,102 @@ 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