From: Thomas Gleixner <tglx@linutronix.de>
To: l@dorileo.org
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
rostedt@goodmis.org, John Kacur <jkacur@redhat.com>,
linux-mm@kvack.org,
Leandro Dorileo <leandro.maciel.dorileo@intel.com>
Subject: Re: [RFC][4.1.15-rt17 PATCH] mm: swap: lru drain don't use workqueue with PREEMPT_RT_FULL
Date: Tue, 12 Jan 2016 13:01:09 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.11.1601121255240.3575@nanos> (raw)
In-Reply-To: <1452473001-10518-1-git-send-email-l@dorileo.org>
On Sun, 10 Jan 2016, l@dorileo.org wrote:
> +#ifdef CONFIG_PREEMPT_RT_FULL
> +void lru_add_drain_all(void)
> +{
> + static DEFINE_MUTEX(lock);
> + int cpu;
> +
> + mutex_lock(&lock);
> + get_online_cpus();
> +
> + for_each_online_cpu(cpu) {
> + smp_call_function_single(cpu, lru_add_drain, NULL, 1);
How is that supposed to work on RT? Not at all, because lru_add_drain() takes
'sleeping' spinlocks and you cannot do that from hard interrupt context.
Enable lockdep (what you should have done before posting) and watch the
fireworks.
Thanks,
tglx
prev parent reply other threads:[~2016-01-12 12:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-11 0:43 l
2016-01-12 12:01 ` Thomas Gleixner [this message]
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