linux-kernel - Re: [PATCH v7 2/3] sched/task: Add the put_task_struct_atomic

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: <20230504152424.GG1744258@hirez.programming.kicks-ass.net>
Date:   Thu, 4 May 2023 17:24:24 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Wander Lairson Costa <wander@...hat.com>
Cc:     Oleg Nesterov <oleg@...hat.com>, Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Ian Rogers <irogers@...gle.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Will Deacon <will@...nel.org>,
        Waiman Long <longman@...hat.com>,
        Boqun Feng <boqun.feng@...il.com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        Valentin Schneider <vschneid@...hat.com>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        Brian Cain <bcain@...cinc.com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "Liam R. Howlett" <Liam.Howlett@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Christian Brauner <brauner@...nel.org>,
        Andrei Vagin <avagin@...il.com>,
        Shakeel Butt <shakeelb@...gle.com>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:PERFORMANCE EVENTS SUBSYSTEM" 
        <linux-perf-users@...r.kernel.org>, Hu Chunyu <chuhu@...hat.com>,
        Paul McKenney <paulmck@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v7 2/3] sched/task: Add the put_task_struct_atomic_safe()
 function

On Thu, May 04, 2023 at 11:55:15AM -0300, Wander Lairson Costa wrote:

> > Then I'm thinking something trivial like so:
> >
> > static inline void put_task_struct(struct task_struct *t)
> > {
> >         if (!refcount_dec_and_test(&t->usage))
> >                 return;
> >
> >         if (IS_ENABLED(CONFIG_PREEMPT_RT) && !preemptible())
> >                 call_rcu(&t->rcu, __put_task_struct_rcu);
> >
> >         __put_task_struct(t);
> > }
> >
> 
> That's what v5 [1] does. What would be the path in this case? Should I
> resend it as v8?

It's almost what v5 does. v5 also has a !in_task() thing. v5 also
violates codingstyle :-)

But yeah.. something like that.