Message-ID: <8632d9c6-7ec7-c3aa-f9e7-fa63cc82f6ae@redhat.com>
Date:   Fri, 17 Feb 2023 14:35:22 -0300
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Subject: Re: [PATCH v2 1/4] sched/task: Add the put_task_struct_atomic_safe
 function
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To:     Wander Lairson Costa <wander@redhat.com>,
        Valentin Schneider <vschneid@redhat.com>,
        Luca Abeni <luca.abeni@santannapisa.it>
Cc:     Oleg Nesterov <oleg@redhat.com>, Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Stafford Horne <shorne@gmail.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>,
        "Liam R. Howlett" <Liam.Howlett@oracle.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Andrei Vagin <avagin@gmail.com>,
        open list <linux-kernel@vger.kernel.org>,
        Paul McKenney <paulmck@kernel.org>
References: <20230120150246.20797-1-wander@redhat.com>
 <20230120150246.20797-2-wander@redhat.com> <20230123163002.GB6268@redhat.com>
 <CAAq0SUk1vfNDuzGbXNftgW4wq4PC_EzMhpq4E=RBQNkOB3f4YQ@mail.gmail.com>
 <xhsmhbkmkdla4.mognet@vschneid.remote.csb>
 <CAAq0SUnUH6DEjwEs2RxRCtkTU121JXpdsV_rZky1d0Bo04=fiQ@mail.gmail.com>
From:   Daniel Bristot de Oliveira <bristot@redhat.com>
In-Reply-To: <CAAq0SUnUH6DEjwEs2RxRCtkTU121JXpdsV_rZky1d0Bo04=fiQ@mail.gmail.com>
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On 1/30/23 08:49, Wander Lairson Costa wrote:
>> Another thing, if you look at release_task_stack(), it either caches the
>> outgoing stack for later use, or frees it via RCU (regardless of
>> PREEMPT_RT). Perhaps we could follow that and just always punt the freeing
>> of the task struct to RCU?
>>
> That's a point. Do you mean doing that even for !PREEMPT_RT?
> 

It seems that Luca Abeni (in Cc) is hitting the bug in the non-rt kernel
with SCHED_DEADLINE...

adding him to the thread.

-- Daniel