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From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	Clark Williams <williams@redhat.com>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	John Kacur <jkacur@redhat.com>
Subject: Re: [RFC][PATCH tip/sched/core] sched/rt: Simplify the IPI rt balancing logic
Date: Mon, 24 Apr 2017 10:57:00 +0200	[thread overview]
Message-ID: <20170424085700.vm2wpn5gac57vb2n@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20170421224929.1a4bbeec@gandalf.local.home>

On Fri, Apr 21, 2017 at 10:49:29PM -0400, Steven Rostedt wrote:
> +#ifdef HAVE_RT_PUSH_IPI
> +	/*
> +	 * For IPI pull requests, loop across the rto_mask.
> +	 */
> +	struct irq_work rto_push_work;
> +	raw_spinlock_t rto_lock;
> +	/* These atomics are updated outside of a lock */
> +	atomic_t rto_loop_next;
> +	atomic_t rto_loop_start;
> +	/* These are only updated and read withn rto_lock */
> +	int rto_loop;
> +	int rto_cpu;
> +#endif

Don't you think it would make sense to place the rto_lock near the
variables it protects? And if those atomics are supposed to increase
performance, do they want to share the same cacheline with the lock?

  parent reply	other threads:[~2017-04-24  8:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-22  2:49 [RFC][PATCH tip/sched/core] sched/rt: Simplify the IPI rt balancing logic Steven Rostedt
2017-04-22 18:41 ` Steven Rostedt
2017-04-24  8:51 ` Peter Zijlstra
2017-04-24 12:43   ` Steven Rostedt
2017-04-24 12:46     ` Steven Rostedt
2017-04-24 12:52     ` Peter Zijlstra
2017-04-24 13:28       ` Steven Rostedt
2017-04-24 13:50         ` Peter Zijlstra
2017-04-24  8:57 ` Peter Zijlstra [this message]
2017-04-24 12:43   ` Steven Rostedt
2017-04-24 15:53 ` [PATCH RT v2] " Steven Rostedt

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