From: Gerd Hoffmann <kraxel@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
Sergio Lopez <slp@redhat.com>,
qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>,
Igor Mammedov <imammedo@redhat.com>,
Richard Henderson <rth@twiddle.net>
Subject: Re: [PATCH 00/13] microvm: add acpi support
Date: Mon, 23 Mar 2020 13:09:48 +0100 [thread overview]
Message-ID: <20200323120948.f6egd7rhfso6276p@sirius.home.kraxel.org> (raw)
In-Reply-To: <20200323065050-mutt-send-email-mst@kernel.org>
On Mon, Mar 23, 2020 at 06:51:10AM -0400, Michael S. Tsirkin wrote:
> On Thu, Mar 19, 2020 at 09:01:04AM +0100, Gerd Hoffmann wrote:
> > I know that not supporting ACPI in microvm is intentional. If you still
> > don't want ACPI this is perfectly fine, you can use the usual -no-acpi
> > switch to toggle ACPI support.
> >
> > These are the advantages you are going to loose then:
> >
> > (1) virtio-mmio device discovery without command line hacks (tweaking
> > the command line is a problem when not using direct kernel boot).
> > (2) Better IO-APIC support, we can use IRQ lines 16-23.
> > (3) ACPI power button (aka powerdown request) works.
> > (4) machine poweroff (aka S5 state) works.
>
> What is the cost though? How do boot times compare?
Well, acpi speeds up booting by one second because this delay ...
[ 0.275736] i8042: PNP: No PS/2 controller found.
[ 0.275736] i8042: Probing ports directly.
[ 1.315447] i8042: No controller found
... goes away, at least with standard distro kernels. When building
your own you can probably compile out the driver somehow, even though
something seems to select SERIO_I8042 so trying to simply flip
CONFIG_SERIO_I8042 to 'n' in .config doesn't work. And a runtime
switch seems to not be there either ...
So that ruined my plan to just time until the root filesystem is
mounted. Decided to use the "i8042: PNP: No PS/2 controller found."
line instead for a simple test (just check the kernel log timestamps,
three runs each). The ACPI initialization is already done at that
point, so it should be useful nevertheless. Here we go:
Without acpi:
0.277710
0.278852
0.279520
With acpi:
0.283917
0.284262
0.284836
So the difference is less than 0.01 seconds on my box.
cheers,
Gerd
next prev parent reply other threads:[~2020-03-23 12:10 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-19 8:01 [PATCH 00/13] microvm: add acpi support Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 01/13] acpi: make build_madt() more generic Gerd Hoffmann
2020-03-19 9:34 ` Philippe Mathieu-Daudé
2020-03-19 8:01 ` [PATCH 02/13] acpi: factor out acpi_dsdt_add_fw_cfg() Gerd Hoffmann
2020-03-19 9:36 ` Philippe Mathieu-Daudé
2020-03-19 12:16 ` Igor Mammedov
2020-03-19 8:01 ` [PATCH 03/13] microvm: add isa-acpi device Gerd Hoffmann
2020-03-19 13:42 ` Igor Mammedov
2020-03-20 8:22 ` Gerd Hoffmann
2020-03-20 14:54 ` Igor Mammedov
2020-03-19 8:01 ` [PATCH 04/13] microvm: add minimal acpi support Gerd Hoffmann
2020-03-19 14:00 ` Igor Mammedov
2020-03-25 9:04 ` Gerd Hoffmann
2020-03-25 18:59 ` Igor Mammedov
2020-03-19 8:01 ` [PATCH 05/13] microvm: add acpi_dsdt_add_virtio() for x86 Gerd Hoffmann
2020-03-19 14:30 ` Igor Mammedov
2020-03-20 8:19 ` Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 06/13] microvm: disable virtio-mmio cmdline hack Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 07/13] [testing] seabios: update submodule to experimental microvm branch Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 08/13] [testing] seabios: update config & build rules Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 09/13] [testing] seabios: update binaries to experimental microvm branch Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 10/13] microvm/acpi: add rtc Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 11/13] microvm/acpi: add serial Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 12/13] microvm: make virtio irq base runtime configurable Gerd Hoffmann
2020-03-19 8:01 ` [PATCH 13/13] microvm/acpi: use GSI 16-23 for virtio Gerd Hoffmann
2020-03-20 15:30 ` Konrad Rzeszutek Wilk
2020-03-23 10:23 ` Gerd Hoffmann
2020-03-19 8:19 ` [PATCH 00/13] microvm: add acpi support no-reply
2020-03-19 8:23 ` no-reply
2020-03-19 8:24 ` no-reply
2020-03-19 8:49 ` Paolo Bonzini
2020-03-19 9:33 ` Gerd Hoffmann
2020-03-19 9:59 ` Paolo Bonzini
2020-03-19 11:28 ` Gerd Hoffmann
2020-03-19 13:40 ` Gerd Hoffmann
2020-03-19 17:34 ` Paolo Bonzini
2020-03-20 8:32 ` Gerd Hoffmann
2020-03-20 10:41 ` Paolo Bonzini
2020-03-23 10:51 ` Michael S. Tsirkin
2020-03-23 12:09 ` Gerd Hoffmann [this message]
2020-03-23 12:16 ` Igor Mammedov
2020-03-25 9:16 ` Gerd Hoffmann
2020-03-25 9:53 ` Igor Mammedov
2020-03-25 18:56 ` Igor Mammedov
2020-03-25 12:32 ` Igor Mammedov
2020-03-25 15:03 ` Gerd Hoffmann
2020-03-25 18:44 ` Igor Mammedov
2020-03-26 7:33 ` Michael S. Tsirkin
2020-03-26 10:59 ` Igor Mammedov
2020-03-27 12:06 ` Gerd Hoffmann
2020-03-27 14:05 ` Igor Mammedov
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=20200323120948.f6egd7rhfso6276p@sirius.home.kraxel.org \
--to=kraxel@redhat.com \
--cc=ehabkost@redhat.com \
--cc=imammedo@redhat.com \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=rth@twiddle.net \
--cc=slp@redhat.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.