From: <Mario.Limonciello@dell.com>
To: <luto@kernel.org>, <pali.rohar@gmail.com>
Cc: <hdegoede@redhat.com>, <kernel@kempniu.pl>,
<dvhart@infradead.org>, <rjw@rjwysocki.net>,
<len.brown@intel.com>, <corentin.chary@gmail.com>,
<andriy.shevchenko@linux.intel.com>,
<linux-kernel@vger.kernel.org>,
<platform-driver-x86@vger.kernel.org>, <linux-pm@vger.kernel.org>
Subject: RE: RFC: WMI Enhancements
Date: Thu, 13 Apr 2017 15:40:08 +0000 [thread overview]
Message-ID: <5bdfff4f72a941d086eeebba71557f19@ausx13mpc120.AMER.DELL.COM> (raw)
In-Reply-To: <CALCETrWOY2Jzj4ht37GUVEisqotPXucEHaaym=HU97CwYh3n8A@mail.gmail.com>
> -----Original Message-----
> From: Andy Lutomirski [mailto:luto@kernel.org]
> Sent: Thursday, April 13, 2017 10:35 AM
> To: Pali Rohár <pali.rohar@gmail.com>
> Cc: Limonciello, Mario <Mario_Limonciello@Dell.com>; Hans de Goede
> <hdegoede@redhat.com>; Michał Kępień <kernel@kempniu.pl>; Darren Hart
> <dvhart@infradead.org>; Rafael J. Wysocki <rjw@rjwysocki.net>; Len Brown
> <len.brown@intel.com>; corentin.chary@gmail.com; Andrew Lutomirski
> <luto@kernel.org>; Andy Shevchenko <andriy.shevchenko@linux.intel.com>;
> linux-kernel@vger.kernel.org; platform-driver-x86@vger.kernel.org; linux-
> pm@vger.kernel.org
> Subject: Re: RFC: WMI Enhancements
>
> On Thu, Apr 13, 2017 at 6:51 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> > On Thursday 13 April 2017 13:29:41 Mario.Limonciello@dell.com wrote:
> >> > Please pardon my ignorance, but what do we actually gain by
> >> > exposing WMI to userspace? Enabling applications to fetch SMBIOS
> >> > data? We already have an interface for that. Enabling applications to
> receive input events? Likewise.
> >>
> >> Input notifications are just one aspect that received over WMI. I
> >> don't see any reason to move the notifications out of the kernel.
> >>
> >> In terms of userspace applications, once a WMI interface to userspace
> >> is available libsmbios would change over to that. Applications using
> libsmbios would benefit.
> >
> > Really libsmbios matters here? Hans (added to thread) wrote that
> > libsmbios is a relic, something of ages long gone by and a normal user
> > should never use it.
> >
> > If this is truth and libsmbios should not be used, then we probably do
> > not need to care about it in changes for WMI.
> >
> > Hans, Mario, any comment/clarification about it?
> >
> >> > You mentioned WMI's efficiency compared to SMI/SMM, but is it a
> >> > difference significant enough for anyone to notice?
> >>
> >> At least for Dell there are optimizations being made when data is
> >> requested over the WMI-ACPI wrapper instead of directly via SMI/SMM.
> >>
> >> For example if the data is a "static" table or the request is to
> >> something that is passed thru to the EC it's a big waste of effort to put the
> CPU in SMM.
> >>
> >> The savings there is significant.
> >
> > Maybe we can use this Dell WMI-ACPI wrapper for kernel drivers instead
> > of current SMI/SMM direct access?
> >
>
> This would make sense to me. IIRC the only functional difference is the way
> that pointers are handled. It shouldn't be that hard to make it work for both
> variants, though. It could look like:
>
> buf = dell_smbios_alloc(...);
> dell_smbios_put_pointer(buf, offset of pointer, offset of pointee);
> dell_smbios_call(buf);
>
> or similar.
Yes, I was going to encourage that kernel change after this WMI discussion
had some conclusions.
next prev parent reply other threads:[~2017-04-13 15:51 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-12 23:08 RFC: WMI Enhancements Darren Hart
2017-04-13 7:32 ` Michał Kępień
2017-04-13 13:29 ` Mario.Limonciello
2017-04-13 13:51 ` Pali Rohár
2017-04-13 15:34 ` Andy Lutomirski
2017-04-13 15:40 ` Mario.Limonciello [this message]
2017-04-13 16:06 ` Darren Hart
2017-04-13 15:40 ` Mario.Limonciello
2017-04-18 7:36 ` Andy Shevchenko
2017-04-18 14:08 ` Mario.Limonciello
2017-04-13 15:32 ` Andy Lutomirski
2017-04-13 15:39 ` Pali Rohár
2017-04-13 15:44 ` Andy Lutomirski
2017-04-13 16:09 ` Darren Hart
2017-04-13 15:55 ` Mario.Limonciello
2017-04-13 15:57 ` Andy Lutomirski
2017-04-13 16:54 ` Mario.Limonciello
2017-04-13 17:06 ` Darren Hart
2017-04-13 17:39 ` Mario.Limonciello
2017-04-13 17:44 ` Andy Lutomirski
2017-04-13 17:49 ` Mario.Limonciello
2017-04-18 7:54 ` Pali Rohár
2017-04-18 16:56 ` Darren Hart
2017-04-18 19:28 ` Pali Rohár
2017-04-13 17:02 ` Darren Hart
2017-04-13 17:32 ` Andy Lutomirski
2017-04-13 17:45 ` Mario.Limonciello
2017-04-13 16:08 ` Darren Hart
2017-04-13 7:33 ` Pali Rohár
2017-04-13 16:56 ` Darren Hart
2017-04-13 20:38 ` Mario.Limonciello
2017-04-13 23:51 ` Darren Hart
2017-04-14 17:42 ` Mario.Limonciello
2017-04-14 18:27 ` Darren Hart
2017-04-14 19:04 ` Mario.Limonciello
2017-04-14 22:45 ` Rafael J. Wysocki
2017-04-14 23:05 ` Darren Hart
2017-04-17 22:03 ` Andy Lutomirski
2017-04-17 23:10 ` Darren Hart
2017-04-18 13:07 ` Rafael J. Wysocki
2017-04-18 16:33 ` Darren Hart
2017-04-18 19:28 ` Pali Rohár
2017-04-18 22:49 ` Darren Hart
2017-04-19 7:52 ` Pali Rohár
2017-04-19 16:29 ` Mario.Limonciello
2017-04-19 16:54 ` Pali Rohár
2017-04-19 17:24 ` Mario.Limonciello
2017-04-20 13:14 ` Pali Rohár
2017-04-20 20:44 ` Darren Hart
2017-05-05 21:55 ` Mario.Limonciello
2017-05-05 23:44 ` Darren Hart
2017-05-06 0:51 ` Mario.Limonciello
2017-05-06 1:25 ` Andy Lutomirski
2017-05-08 15:29 ` Darren Hart
2017-05-08 15:36 ` Mario.Limonciello
2017-05-08 15:47 ` Darren Hart
2017-05-08 16:00 ` Mario.Limonciello
2017-05-08 16:04 ` Andy Shevchenko
[not found] ` <CAOg5c--wkQgvsmhTynAKyG9iWaHjRWC5Z+MXzVJVw66vxSz4Zw@mail.gmail.com>
2017-05-08 18:26 ` Mario.Limonciello
2017-05-08 19:09 ` Darren Hart
2017-05-08 19:11 ` Mario.Limonciello
2017-05-08 17:17 ` Pali Rohár
2017-05-08 19:21 ` Mario.Limonciello
2017-05-08 20:59 ` Pali Rohár
2017-05-08 21:18 ` Mario.Limonciello
2017-05-08 22:17 ` Pali Rohár
2017-05-09 1:10 ` Mario.Limonciello
2017-05-09 7:29 ` Pali Rohár
2017-05-09 18:10 ` Mario.Limonciello
2017-05-09 19:04 ` Andy Shevchenko
2017-05-09 19:16 ` Mario.Limonciello
2017-05-09 19:26 ` Andy Shevchenko
2017-05-09 22:38 ` Pali Rohár
2017-05-09 19:19 ` Pali Rohár
2017-04-20 14:17 ` Christoph Hellwig
2017-04-18 21:14 ` Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5bdfff4f72a941d086eeebba71557f19@ausx13mpc120.AMER.DELL.COM \
--to=mario.limonciello@dell.com \
--cc=andriy.shevchenko@linux.intel.com \
--cc=corentin.chary@gmail.com \
--cc=dvhart@infradead.org \
--cc=hdegoede@redhat.com \
--cc=kernel@kempniu.pl \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=luto@kernel.org \
--cc=pali.rohar@gmail.com \
--cc=platform-driver-x86@vger.kernel.org \
--cc=rjw@rjwysocki.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).