From: Ian Campbell <ian.campbell@citrix.com>
To: Andrii Tseglytskyi <andrii.tseglytskyi@globallogic.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com>,
Tim Deegan <tim@xen.org>, xen-devel <xen-devel@lists.xen.org>,
Stefano Stabellini <Stefano.Stabellini@citrix.com>,
Jan Beulich <JBeulich@suse.com>
Subject: Re: [RFC PATCH 11/13] cpufreq: add xen-cpufreq driver
Date: Wed, 15 Oct 2014 13:34:53 +0100 [thread overview]
Message-ID: <1413376493.10417.87.camel@citrix.com> (raw)
In-Reply-To: <CAH_mUMMX1Q+EhLR079qou8iwrCmZ7FCV4a0sOeFe1SmJFHGgdw@mail.gmail.com>
On Wed, 2014-10-15 at 14:17 +0300, Andrii Tseglytskyi wrote:
> > Jan and I have been discussing this face to face yesterday (thanks to
> > LinuxCon being located in Germany this year).
> >
> > We should keep in mind that actually both approaches can coexist and we
> > should be able to choose the best one for each platform.
> >
>
> What if we try to implement both and see which one is better? But I
> would prefer to implement solution without I2C in hypervisor frirst ))
> And post it as RFC of course.
My preference would be to implement the in hypervisor based one first
(since this is the architecturally cleaner option) and then only do the
out of hypervisor one if it turns out to be unworkable in practice.
> > Also it would be nice to know how many I2C bus accesses per seconds the
> > drivers on your board actually make. You could take a measurement by
> > editing your Linux kernel and adding a counter in the I2C subsystem.
> >
>
> IMO - synchronization of I2C access between dom0 and hypervisot will be painful.
I think this supposition needs backing with evidence of the type Stefano
is asking for, or by actually building it and showing it doesn't work on
this particular platform.
Ian.
next prev parent reply other threads:[~2014-10-15 12:34 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-07 14:19 [RFC PATCH 00/13] xen_cpufreq implementation in Xen hypervisor Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 01/13] cpufreq: move cpufreq.h file to the xen/include/cpufreq location Oleksandr Dmytryshyn
2014-10-07 14:22 ` Andrew Cooper
2014-10-07 14:27 ` Oleksandr Dmytryshyn
2014-10-07 14:35 ` Jan Beulich
2014-10-09 6:04 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 02/13] pm: move processor_perf.h " Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 03/13] pmstat: move pmstat.c file to the xen/drivers/pm location Oleksandr Dmytryshyn
2014-10-07 14:38 ` Jan Beulich
2014-10-09 6:05 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 04/13] cpufreq: use turbo settings only for x86 architecture Oleksandr Dmytryshyn
2014-10-07 14:39 ` Jan Beulich
2014-10-09 6:05 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 05/13] pmstat: make pmstat functions more generalizable Oleksandr Dmytryshyn
2014-10-07 14:40 ` Jan Beulich
2014-10-09 6:06 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 06/13] cpufreq: make cpufreq driver " Oleksandr Dmytryshyn
2014-10-07 14:42 ` Jan Beulich
2014-10-09 6:06 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 07/13] xen/arm: enable cpu hotplug Oleksandr Dmytryshyn
2014-10-07 15:15 ` Julien Grall
2014-10-09 6:07 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 08/13] xen/dts: make the dt_find_property function to be global Oleksandr Dmytryshyn
2014-10-07 15:09 ` Julien Grall
2014-10-09 6:09 ` Oleksandr Dmytryshyn
2014-10-09 11:15 ` Julien Grall
2014-10-09 11:40 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 09/13] arch/arm: create device tree nodes for Dom0 cpufreq cpu driver Oleksandr Dmytryshyn
2014-10-07 15:26 ` Julien Grall
2014-10-09 6:10 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 10/13] xen: arm: implement platform hypercall Oleksandr Dmytryshyn
2014-10-07 15:39 ` Julien Grall
2014-10-09 6:11 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 11/13] cpufreq: add xen-cpufreq driver Oleksandr Dmytryshyn
2014-10-07 14:44 ` Jan Beulich
2014-10-08 13:51 ` Stefano Stabellini
2014-10-10 9:00 ` Jan Beulich
2014-10-10 9:04 ` Stefano Stabellini
2014-10-10 9:39 ` Jan Beulich
2014-10-10 9:39 ` Stefano Stabellini
2014-10-10 9:46 ` Jan Beulich
2014-10-10 9:54 ` Stefano Stabellini
2014-10-10 9:59 ` Ian Campbell
2014-10-10 12:51 ` Jan Beulich
2014-10-10 14:42 ` Stefano Stabellini
2014-10-13 8:56 ` Oleksandr Dmytryshyn
2014-10-13 9:39 ` Jan Beulich
2014-10-13 11:59 ` Oleksandr Dmytryshyn
2014-10-13 12:28 ` Jan Beulich
2014-10-13 13:38 ` Andrii Tseglytskyi
2014-10-13 14:11 ` Jan Beulich
2014-10-13 14:29 ` Andrii Tseglytskyi
2014-10-14 12:20 ` Jan Beulich
2014-10-14 12:39 ` Andrii Tseglytskyi
2014-10-14 12:51 ` Stefano Stabellini
2014-10-14 12:58 ` Andrii Tseglytskyi
2014-10-14 13:00 ` Andrii Tseglytskyi
2014-10-14 13:05 ` Ian Campbell
2014-10-14 13:07 ` Andrii Tseglytskyi
2014-10-15 10:55 ` Stefano Stabellini
2014-10-15 11:17 ` Andrii Tseglytskyi
2014-10-15 12:34 ` Ian Campbell [this message]
2014-10-15 16:26 ` Jan Beulich
2014-10-10 15:19 ` Ian Campbell
2014-10-10 10:40 ` Jan Beulich
2014-10-09 6:13 ` Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 12/13] xen: arm: implement XEN_SYSCTL_cpufreq_op Oleksandr Dmytryshyn
2014-10-07 14:19 ` [RFC PATCH 13/13] xen/arm: enable cpufreq functionality for ARM Oleksandr Dmytryshyn
2014-10-07 14:34 ` [RFC PATCH 00/13] xen_cpufreq implementation in Xen hypervisor Jan Beulich
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