From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Wander Lairson Costa <wander@redhat.com>,
Oleg Nesterov <oleg@redhat.com>, Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Will Deacon <will@kernel.org>, Waiman Long <longman@redhat.com>,
Boqun Feng <boqun.feng@gmail.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Brian Cain <bcain@quicinc.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christian Brauner <brauner@kernel.org>,
Andrei Vagin <avagin@gmail.com>,
Shakeel Butt <shakeelb@google.com>,
open list <linux-kernel@vger.kernel.org>,
"open list:PERFORMANCE EVENTS SUBSYSTEM"
<linux-perf-users@vger.kernel.org>, Hu Chunyu <chuhu@redhat.com>,
Paul McKenney <paulmck@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v7 2/3] sched/task: Add the put_task_struct_atomic_safe() function
Date: Fri, 5 May 2023 10:29:16 -0400 [thread overview]
Message-ID: <20230505102916.4aa664dd@gandalf.local.home> (raw)
In-Reply-To: <20230505102602.2052c83a@gandalf.local.home>
On Fri, 5 May 2023 10:26:02 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> > > IIRC, the in_task() is there because preemptible() doesn't check if it
> > > is running in interrupt context.
> >
> > #define preemptible() (preempt_count() == 0 && !irqs_disabled())
> >
> > When in interrupt context preempt_count() will have a non-zero value in
> > HARDIRQ_MASK and IRQs must be disabled, so preemptible() evaluates to
> > (false && false), last time I checked that ends up being false.
>
> Interesting, I can't find v5 anywhere in my mail folders (but I have
> v4 and v6!). Anyway, from just the context of this email, and seeing
> IS_ENABLED(CONFIG_PREEMPT_RT), I'm guessing that in_task() returns false if
> it's running in a interrupt thread, where preemtible() does not.
But then I question, does it matter if it is running in an interrupt thread
or not for put_task_struct()?
-- Steve
next prev parent reply other threads:[~2023-05-05 14:29 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-25 11:43 [PATCH v7 0/3] Introduce put_task_struct_atomic_sleep() Wander Lairson Costa
2023-04-25 11:43 ` [PATCH v7 1/3] sched/core: warn on call put_task_struct in invalid context Wander Lairson Costa
2023-04-28 16:17 ` Sebastian Andrzej Siewior
2023-05-02 14:46 ` Wander Lairson Costa
2023-04-25 11:43 ` [PATCH v7 2/3] sched/task: Add the put_task_struct_atomic_safe() function Wander Lairson Costa
2023-05-04 8:42 ` Peter Zijlstra
2023-05-04 9:32 ` Valentin Schneider
2023-05-04 12:24 ` Wander Lairson Costa
2023-05-04 12:24 ` Wander Lairson Costa
2023-05-04 12:29 ` Oleg Nesterov
2023-05-04 14:33 ` Peter Zijlstra
2023-05-04 14:55 ` Wander Lairson Costa
2023-05-04 15:23 ` Oleg Nesterov
2023-05-04 15:30 ` Peter Zijlstra
2023-05-05 13:39 ` Peter Zijlstra
2023-05-04 18:29 ` Wander Lairson Costa
2023-05-04 19:22 ` Oleg Nesterov
2023-05-04 19:38 ` Wander Lairson Costa
2023-05-04 20:16 ` Oleg Nesterov
2023-05-08 12:30 ` Wander Lairson Costa
2023-05-04 15:24 ` Peter Zijlstra
2023-05-04 18:21 ` Wander Lairson Costa
2023-05-05 13:32 ` Peter Zijlstra
2023-05-05 14:26 ` Steven Rostedt
2023-05-05 14:29 ` Steven Rostedt [this message]
2023-05-08 12:28 ` Wander Lairson Costa
2023-04-25 11:43 ` [PATCH v7 3/3] treewide: replace put_task_struct() with the atomic safe version Wander Lairson Costa
2023-04-26 12:05 ` [PATCH v7 0/3] Introduce put_task_struct_atomic_sleep() Valentin Schneider
2023-04-26 17:44 ` Waiman Long
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