From: Peter Zijlstra <peterz@infradead.org>
To: "Ofer Levi(SW)" <oferle@mellanox.com>
Cc: "rusty@rustcorp.com.au" <rusty@rustcorp.com.au>,
"vatsa@in.ibm.com" <vatsa@in.ibm.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"Vineet.Gupta1@synopsys.com" <Vineet.Gupta1@synopsys.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: hotplug support for arch/arc/plat-eznps platform
Date: Mon, 7 Aug 2017 10:33:54 +0200 [thread overview]
Message-ID: <20170807083354.ptkehfql54xydsvm@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <VI1PR0501MB2110D6262D092D202C30E6C5B2B40@VI1PR0501MB2110.eurprd05.prod.outlook.com>
On Sun, Aug 06, 2017 at 05:53:37AM +0000, Ofer Levi(SW) wrote:
> I'm adding hot-plug support for the above arch and ran into performance issue with execution of
> partition_sched_domains () - About 0.5 sec per cpu, which is unacceptable with the arch supported 4k cpus.
> To my limited understanding, on the plat-eznps arch, where each cpu is always running a single threaded process in
> isolation mode, the above call is not necessary,
> Can you please confirm (or reject) my understanding? If I'm wrong short explanation will be appreciated.
> If I'm correct, I will be grateful if you can point me to how to skip this call in a way acceptable by community.
You've failed to explain why you think hotplug should be a performance
critical path.
I'm also not seeing how it would be different from boot; you'd be
looking at a similar cost for SMP bringup.
next prev parent reply other threads:[~2017-08-07 8:34 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-06 5:53 Ofer Levi(SW)
2017-08-07 8:33 ` Peter Zijlstra [this message]
2017-08-07 13:41 ` Ofer Levi(SW)
2017-08-07 15:10 ` Peter Zijlstra
2017-08-08 6:49 ` Ofer Levi(SW)
2017-08-08 10:16 ` Peter Zijlstra
2017-08-09 15:19 ` Ofer Levi(SW)
2017-08-09 15:34 ` Peter Zijlstra
2017-08-10 7:40 ` Ofer Levi(SW)
2017-08-10 9:19 ` Peter Zijlstra
2017-08-10 11:51 ` Ofer Levi(SW)
2017-08-10 15:45 ` Peter Zijlstra
2017-08-14 7:54 ` Ofer Levi(SW)
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