From: Peter Zijlstra <peterz@infradead.org>
To: Venkatesh Pallipadi <venki@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Aaron Durbin <adurbin@google.com>, Paul Turner <pjt@google.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] Extend mwait idle to optimize away IPIs when possible
Date: Fri, 10 Feb 2012 20:19:27 +0100 [thread overview]
Message-ID: <1328901567.25989.51.camel@laptop> (raw)
In-Reply-To: <1328560933-3037-1-git-send-email-venki@google.com>
On Mon, 2012-02-06 at 12:42 -0800, Venkatesh Pallipadi wrote:
> smp_call_function_single and ttwu_queue_remote sends unconditional IPI
> to target CPU. However, if the target CPU is in mwait based idle, we can
> do IPI-less wakeups using the magical powers of monitor-mwait.
So I was thinking, why not change native_smp_send_reschedule() and
native_send_call_func_single_ipi() and keep the change entirely inside
the arch?
Ideally its only APIC/idle that know about this detail, the scheduler
(or other consumers) really don't care about how the other cpu comes to
run the callback.
next prev parent reply other threads:[~2012-02-10 19:19 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-06 20:42 [RFC] Extend mwait idle to optimize away IPIs when possible Venkatesh Pallipadi
2012-02-06 21:02 ` Peter Zijlstra
2012-02-06 21:26 ` Venki Pallipadi
2012-02-07 0:26 ` David Daney
2012-02-07 1:24 ` H. Peter Anvin
2012-02-07 1:34 ` David Daney
2012-02-07 1:45 ` H. Peter Anvin
2012-02-07 2:03 ` Venki Pallipadi
2012-02-07 2:24 ` Suresh Siddha
2012-02-07 21:39 ` Venki Pallipadi
2012-02-08 6:51 ` Yong Zhang
2012-02-08 23:28 ` Venki Pallipadi
2012-02-09 2:18 ` Yong Zhang
2012-02-10 2:17 ` Venki Pallipadi
2012-02-13 5:27 ` Yong Zhang
2012-02-10 19:19 ` Peter Zijlstra [this message]
2012-02-11 2:11 ` Venki Pallipadi
2012-02-11 3:09 ` Peter Zijlstra
2012-02-13 5:34 ` Yong Zhang
2012-02-14 13:52 ` Peter Zijlstra
2012-02-15 1:39 ` Yong Zhang
2012-02-15 2:32 ` Venki Pallipadi
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