From: Oleg Nesterov <oleg@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Sebastian Siewior <bigeasy@linutronix.de>,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Julia Cartwright <julia@ni.com>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
John Stultz <john.stultz@linaro.org>,
Andy Lutomirski <luto@kernel.org>,
"Paul E. McKenney" <paulmck@linux.ibm.com>,
kvm@vger.kernel.org, Radim Krcmar <rkrcmar@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [patch 4/5] posix-cpu-timers: Defer timer handling to task_work
Date: Thu, 1 Aug 2019 17:39:36 +0200 [thread overview]
Message-ID: <20190801153936.GD31538@redhat.com> (raw)
In-Reply-To: <20190801143658.074833024@linutronix.de>
On 08/01, Thomas Gleixner wrote:
>
> +static void __run_posix_cpu_timers(struct task_struct *tsk)
> +{
> + /* FIXME: Init it proper in fork or such */
> + init_task_work(&tsk->cpu_timer_work, posix_cpu_timers_work);
> + task_work_add(tsk, &tsk->cpu_timer_work, true);
> +}
What if update_process_times/run_posix_cpu_timers is called again before
this task does task_work_run() ?
somehow it should check that ->cpu_timer_work is not already queued...
Or suppose that this is called when task_work_run() executes this
cpu_timer_work. Looks like you need another flag checked by
__run_posix_cpu_timers() and cleare in posix_cpu_timers_work() ?
Oleg.
next prev parent reply other threads:[~2019-08-01 15:39 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-01 14:32 [patch 0/5] posix-cpu-timers: Move expiry into task work context Thomas Gleixner
2019-08-01 14:32 ` [patch 1/5] tracehook: Provide TIF_NOTIFY_RESUME handling for KVM Thomas Gleixner
2019-08-01 14:48 ` Peter Zijlstra
2019-08-01 15:10 ` Thomas Gleixner
2019-08-01 17:02 ` Andy Lutomirski
2019-08-01 14:32 ` [patch 2/5] x86/kvm: Handle task_work on VMENTER/EXIT Thomas Gleixner
2019-08-01 16:24 ` Oleg Nesterov
2019-08-01 18:34 ` Thomas Gleixner
2019-08-01 21:35 ` Sean Christopherson
2019-08-01 21:44 ` Peter Zijlstra
2019-08-01 21:44 ` Thomas Gleixner
2019-08-01 21:47 ` Thomas Gleixner
2019-08-02 21:35 ` Paolo Bonzini
2019-08-02 22:22 ` Thomas Gleixner
2019-08-02 22:39 ` Andy Lutomirski
2019-08-02 12:04 ` Oleg Nesterov
2019-08-01 14:32 ` [patch 3/5] posix-cpu-timers: Split run_posix_cpu_timers() Thomas Gleixner
2019-08-01 14:32 ` [patch 4/5] posix-cpu-timers: Defer timer handling to task_work Thomas Gleixner
2019-08-01 14:51 ` Peter Zijlstra
2019-08-01 15:10 ` Thomas Gleixner
2019-08-01 15:39 ` Oleg Nesterov [this message]
2019-08-01 18:41 ` Thomas Gleixner
2019-08-01 14:32 ` [patch 5/5] x86: Select POSIX_CPU_TIMERS_TASK_WORK Thomas Gleixner
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