From: "Michael S. Tsirkin" <mst@redhat.com>
To: Laszlo Ersek <lersek@redhat.com>
Cc: peter.maydell@linaro.org, marcel.a@redhat.com,
"Andreas Färber" <afaerber@suse.de>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 2/2] machine_parse(): list supported machine types in their registration order
Date: Mon, 22 Sep 2014 15:36:41 +0300 [thread overview]
Message-ID: <20140922123641.GB7992@redhat.com> (raw)
In-Reply-To: <54201614.6040903@redhat.com>
On Mon, Sep 22, 2014 at 02:29:08PM +0200, Laszlo Ersek wrote:
> On 09/22/14 14:04, Andreas Färber wrote:
> > Am 22.09.2014 um 13:26 schrieb Laszlo Ersek:
> >> Based on the registration order captured in the previous patch, we
> >> sort the ad-hoc list printed for
> >>
> >> qemu-system-XXXX -M \?
> >
> > Agree that the order is worth sanitizing. I would however argue that
> > registration order is not entirely stable either if you think of
> > non-PC cases where there's dozens of source files registering one
> > machine each. I would therefore propose alphabetical order as we do
> > for QOM'ified CPUs.
>
> I did mention alphabetical order in the message of patch #1 -- in fact
> that was what I implemented first:
>
> > The first idea to restore ordering is to sort the ad-hoc list in
> > machine_parse() by "MachineClass.name". Such a name-based ordering
> > would have to be reverse, so that more recent versioned machine types
> > appear higher on the list than older versioned machine types (eg. with
> > qemu-system-x86_64). However, such a reverse sort wreaks havoc between
> > non-versioned machine types (such as those of qemu-system-aarch64).
>
> Simply put, it looks very ugly. Namely, if you sort it in alphabetically
> *ascending* order, then for the x86_64 target, you get:
>
> > isapc ISA-only PC
> > none empty machine
> > pc Standard PC (i440FX + PIIX, 1996) (alias of pc-i440fx-2.2)
> > pc-0.10 Standard PC (i440FX + PIIX, 1996)
> > pc-0.11 Standard PC (i440FX + PIIX, 1996)
> > pc-0.12 Standard PC (i440FX + PIIX, 1996)
> > pc-0.13 Standard PC (i440FX + PIIX, 1996)
> > pc-0.14 Standard PC (i440FX + PIIX, 1996)
> > pc-0.15 Standard PC (i440FX + PIIX, 1996)
> > pc-1.0 Standard PC (i440FX + PIIX, 1996)
> > pc-1.1 Standard PC (i440FX + PIIX, 1996)
> > pc-1.2 Standard PC (i440FX + PIIX, 1996)
> > pc-1.3 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.4 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.5 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.6 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.7 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-2.0 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-2.1 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-2.2 Standard PC (i440FX + PIIX, 1996) (default)
> > pc-q35-1.4 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.5 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.6 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.7 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-2.0 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-2.1 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-2.2 Standard PC (Q35 + ICH9, 2009)
> > q35 Standard PC (Q35 + ICH9, 2009) (alias of pc-q35-2.2)
>
> which is very bad / unusual. Okay, so let's sort it in alphabetically
> descending order:
>
> > q35 Standard PC (Q35 + ICH9, 2009) (alias of pc-q35-2.2)
> > pc-q35-2.2 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-2.1 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-2.0 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.7 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.6 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.5 Standard PC (Q35 + ICH9, 2009)
> > pc-q35-1.4 Standard PC (Q35 + ICH9, 2009)
> > pc-i440fx-2.2 Standard PC (i440FX + PIIX, 1996) (default)
> > pc-i440fx-2.1 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-2.0 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.7 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.6 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.5 Standard PC (i440FX + PIIX, 1996)
> > pc-i440fx-1.4 Standard PC (i440FX + PIIX, 1996)
> > pc-1.3 Standard PC (i440FX + PIIX, 1996)
> > pc-1.2 Standard PC (i440FX + PIIX, 1996)
> > pc-1.1 Standard PC (i440FX + PIIX, 1996)
> > pc-1.0 Standard PC (i440FX + PIIX, 1996)
> > pc-0.15 Standard PC (i440FX + PIIX, 1996)
> > pc-0.14 Standard PC (i440FX + PIIX, 1996)
> > pc-0.13 Standard PC (i440FX + PIIX, 1996)
> > pc-0.12 Standard PC (i440FX + PIIX, 1996)
> > pc-0.11 Standard PC (i440FX + PIIX, 1996)
> > pc-0.10 Standard PC (i440FX + PIIX, 1996)
> > pc Standard PC (i440FX + PIIX, 1996) (alias of pc-i440fx-2.2)
> > none empty machine
> > isapc ISA-only PC
>
> Okay, this is certainly bearable. However, let's see what the reverse
> alpha sort does to aarch64:
>
> > z2 Zipit Z2 (PXA27x)
> > xilinx-zynq-a9 Xilinx Zynq Platform Baseboard for Cortex-A9
> > virt ARM Virtual Machine
> > vexpress-a9 ARM Versatile Express for Cortex-A9
> > vexpress-a15 ARM Versatile Express for Cortex-A15
> > versatilepb ARM Versatile/PB (ARM926EJ-S)
> > versatileab ARM Versatile/AB (ARM926EJ-S)
> > verdex Gumstix Verdex (PXA270)
> > tosa Tosa PDA (PXA255)
> > terrier Terrier PDA (PXA270)
> > sx1-v1 Siemens SX1 (OMAP310) V1
> > sx1 Siemens SX1 (OMAP310) V2
> > spitz Spitz PDA (PXA270)
> > smdkc210 Samsung SMDKC210 board (Exynos4210)
> > realview-pbx-a9 ARM RealView Platform Baseboard Explore for Cortex-A9
> > realview-pb-a8 ARM RealView Platform Baseboard for Cortex-A8
> > realview-eb-mpcore ARM RealView Emulation Baseboard (ARM11MPCore)
> > realview-eb ARM RealView Emulation Baseboard (ARM926EJ-S)
> > nuri Samsung NURI board (Exynos4210)
> > none empty machine
> > n810 Nokia N810 tablet aka. RX-44 (OMAP2420)
> > n800 Nokia N800 tablet aka. RX-34 (OMAP2420)
> > musicpal Marvell 88w8618 / MusicPal (ARM926EJ-S)
> > midway Calxeda Midway (ECX-2000)
> > mainstone Mainstone II (PXA27x)
> > lm3s811evb Stellaris LM3S811EVB
> > lm3s6965evb Stellaris LM3S6965EVB
> > kzm ARM KZM Emulation Baseboard (ARM1136)
> > integratorcp ARM Integrator/CP (ARM926EJ-S)
> > highbank Calxeda Highbank (ECX-1000)
> > cubieboard cubietech cubieboard
> > connex Gumstix Connex (PXA255)
> > collie Collie PDA (SA-1110)
> > cheetah Palm Tungsten|E aka. Cheetah PDA (OMAP310)
> > canon-a1100 Canon PowerShot A1100 IS
> > borzoi Borzoi PDA (PXA270)
> > akita Akita PDA (PXA270)
>
> Ugh? The reverse sort is painfully obvious, and the user wonders why it
> is necessary. Why is z2 at the top, and akita at the bottom? Why is n810
> above n800 and not below it? And so on.
>
> Instead, the patchset restores the behavior that had been visible before
> commit 261747f1: programmer-controlled logical order *within* clusters,
> and unspecified order *between* clusters.
We could add a cluster name in the API.
Use that for sort between clusters only.
Hmm?
> IOW, I tested your idea (because it was my first idea as well), and I
> thought (and still think) that alpha sort is inferior to the
> pre-261747f1 order.
>
> Thanks,
> Laszlo
next prev parent reply other threads:[~2014-09-22 12:33 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-22 11:26 [Qemu-devel] [PATCH 0/2] list supported machine types in their registration order Laszlo Ersek
2014-09-22 11:26 ` [Qemu-devel] [PATCH 1/2] save registration order of machine types Laszlo Ersek
2014-09-22 11:26 ` [Qemu-devel] [PATCH 2/2] machine_parse(): list supported machine types in their registration order Laszlo Ersek
2014-09-22 12:04 ` Andreas Färber
2014-09-22 12:26 ` Michael S. Tsirkin
2014-09-22 12:29 ` Laszlo Ersek
2014-09-22 12:36 ` Michael S. Tsirkin [this message]
2014-09-22 12:50 ` Marcel Apfelbaum
2014-09-22 13:43 ` Laszlo Ersek
2014-09-22 15:07 ` Marcel Apfelbaum
2014-09-22 13:15 ` Laszlo Ersek
2014-09-22 15:57 ` Paolo Bonzini
2014-09-22 16:06 ` Andreas Färber
2014-09-22 16:17 ` Paolo Bonzini
2014-09-22 16:13 ` Laszlo Ersek
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=20140922123641.GB7992@redhat.com \
--to=mst@redhat.com \
--cc=afaerber@suse.de \
--cc=lersek@redhat.com \
--cc=marcel.a@redhat.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
/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).