From: Steven Rostedt <rostedt@goodmis.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
linux-rt-users <linux-rt-users@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Daniel Wagner <wagi@monom.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] sched/rt: Do not do push/pull when there is only one CPU
Date: Sat, 2 Dec 2017 12:12:52 -0500 [thread overview]
Message-ID: <20171202121252.0bada310@vmware.local.home> (raw)
In-Reply-To: <20171202125330.xrxspjeedbpr4hk5@linutronix.de>
On Sat, 2 Dec 2017 13:53:31 +0100
Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
> what about a check next to sched_feat(RT_PUSH_IPI)? I don't know if this
> is a hot path or not (due to bitmap_weight). If it is, then I would
> suggest something like a jump-label which is enabled if more than one
> CPU has been enabled on boot.
Yeah I didn't like that because of the overhead. But I was being
optimistic that the cpu weight function would be a nit to the actual
pull logic. But I have a better plan.
I would like to disable RT_PUSH_IPI, but that's a sched feature and
that is a constant if we build without sched debugging.
v2 coming up.
-- Steve
next prev parent reply other threads:[~2017-12-02 17:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-01 18:32 [PATCH] sched/rt: Do not do push/pull when there is only one CPU Steven Rostedt
2017-12-02 12:53 ` Sebastian Andrzej Siewior
2017-12-02 13:55 ` Peter Zijlstra
2017-12-02 17:12 ` Steven Rostedt [this message]
2017-12-02 18:05 ` Steven Rostedt
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