linux-kernel - Re: [PATCH] tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Y8o9Mh1ktK0jdQy9@kroah.com>
Date:   Fri, 20 Jan 2023 08:05:22 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     "Joel Fernandes (Google)" <joel@...lfernandes.org>
Cc:     linux-kernel@...r.kernel.org,
        Frederic Weisbecker <frederic@...nel.org>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Zhouyi Zhou <zhouzhouyi@...il.com>,
        Will Deacon <will@...nel.org>, Marc Zyngier <maz@...nel.org>,
        rcu <rcu@...r.kernel.org>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Ingo Molnar <mingo@...nel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH] tick/nohz: Fix cpu_is_hotpluggable() by checking with
 nohz subsystem

On Thu, Jan 19, 2023 at 08:44:35PM +0000, Joel Fernandes (Google) wrote:
> For CONFIG_NO_HZ_FULL systems, the tick_do_timer_cpu cannot be offlined.
> However, cpu_is_hotpluggable() still returns true for those CPUs. This causes
> torture tests that do offlining to end up trying to offline this CPU causing
> test failures. Such failure happens on all architectures.
> 
> Fix it by asking the opinion of the nohz subsystem on whether the CPU can
> be hotplugged.
> 
> [ Apply Frederic Weisbecker feedback on refactoring tick_nohz_cpu_down(). ]
> 
> Cc: Frederic Weisbecker <frederic@...nel.org>
> Cc: "Paul E. McKenney" <paulmck@...nel.org>
> Cc: Zhouyi Zhou <zhouzhouyi@...il.com>
> Cc: Will Deacon <will@...nel.org>
> Cc: Marc Zyngier <maz@...nel.org>
> Cc: rcu <rcu@...r.kernel.org>
> Fixes: 2987557f52b9 ("driver-core/cpu: Expose hotpluggability to the rest of the kernel")
> Signed-off-by: Joel Fernandes (Google) <joel@...lfernandes.org>

Also want to cc: stable on the patch?

Anyway, for the driver core portion:

Acked-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>