Original Xbox Emulator for Windows, macOS, and Linux (Active Development)
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Markus Armbruster 0dde9fd12f qom: Make info qom-tree sort children more efficiently
Commit e8c9e65816 "qom: Make "info qom-tree" show children sorted"
sorts children the simple, stupid, quadratic way.  I thought the
number of children would be small enough for this not to matter.  I
was wrong: there are outliers with several hundred children, e.g ARM
machines nuri and smdkc210 each have a node with 513 children.

While n^2 sorting isn't noticeable in normal, human usage even for
n=513, it can be quite noticeable in certain automated tests.  In
particular, the sort made device-introspect-test even slower.  Commit
3e7b80f84d "tests: improve performance of device-introspect-test" just
fixed that by cutting back its excessive use of "info qom-tree".
Sorting more efficiently makes sense regardless, so do it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-6-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-07-21 17:39:37 +02:00
.github
.gitlab-ci.d gitlab-ci/containers: Add missing wildcard where we should look for changes 2020-07-15 11:52:43 +01:00
accel tcg/cpu-exec: precise single-stepping after an interrupt 2020-07-17 11:09:34 -07:00
audio ossaudio: fix out of bounds write 2020-07-13 11:38:40 +02:00
authz
backends qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
block qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
bsd-user
capstone@22ead3e0bf
chardev chardev: Extract system emulation specific code 2020-07-13 11:59:47 +04:00
contrib
crypto
default-configs hw/avr: Add limited support for some Arduino boards 2020-07-11 11:02:05 +02:00
disas disas/sh4: Add missing fallthrough annotations 2020-07-13 11:40:52 +02:00
docs docs/system: Document the arm virt board 2020-07-20 11:35:17 +01:00
dtc@85e5d83984
dump
fpu fpu/softfloat: fix up float16 nan recognition 2020-07-15 11:52:43 +01:00
fsdev
gdb-xml
hw qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
include qom: Document object_get_canonical_path() returns malloced string 2020-07-21 16:23:43 +02:00
io
libdecnumber
linux-headers
linux-user linux-user: fix print_syscall_err() when syscall returned value is negative 2020-07-14 09:29:14 +02:00
migration migration/block-dirty-bitmap: fix add_bitmaps_to_list 2020-07-17 08:18:51 -05:00
monitor monitor/misc: Remove unused "chardev/char-mux.h" include 2020-07-13 11:59:47 +04:00
nbd nbd: make nbd_export_close_all() synchronous 2020-07-17 14:20:57 +02:00
net qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
pc-bios pseries: Update SLOF firmware image 2020-07-20 09:21:39 +10:00
plugins
po
python/qemu python/qmp.py: add QMPProtocolError 2020-07-14 22:22:22 +02:00
qapi Remove VXHS block device 2020-07-17 14:20:57 +02:00
qga qga: Use qemu_get_host_name() instead of g_get_host_name() 2020-07-13 17:44:58 -05:00
qobject
qom qom: Make info qom-tree sort children more efficiently 2020-07-21 17:39:37 +02:00
replay
roms pseries: Update SLOF firmware image 2020-07-20 09:21:39 +10:00
scripts python/qmp.py: re-absorb MonitorResponseError 2020-07-14 22:22:22 +02:00
scsi qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
slirp@2faae0f778
softmmu qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
storage-daemon
stubs
target hw/arm/virt: Enable MTE via a machine property 2020-07-20 11:35:15 +01:00
tcg tcg: Save/restore vecop_list around minmax fallback 2020-07-16 13:09:22 -07:00
tests Block layer patches: 2020-07-17 14:58:13 +01:00
tools/virtiofsd
trace
ui bugfixes for audio, usb, ui and docs. 2020-07-13 16:58:44 +01:00
util util: Implement qemu_get_thread_id() for OpenBSD 2020-07-20 11:35:17 +01:00
.cirrus.yml .cirrus.yml: add bash to the brew packages 2020-07-11 15:53:29 +01:00
.dir-locals.el
.editorconfig
.exrc
.gdbinit
.gitignore .gitignore: un-ignore .gitlab-ci.d 2020-07-11 15:53:00 +01:00
.gitlab-ci.yml gitlab-ci.yml: Add fuzzer tests 2020-07-17 10:44:23 +02:00
.gitmodules
.gitpublish
.mailmap
.patchew.yml
.readthedocs.yml
.shippable.yml shippable: pull images from registry instead of building 2020-07-11 15:53:00 +01:00
.travis.yml .travis.yml: skip ppc64abi32-linux-user with plugins 2020-07-15 11:57:17 +01:00
block.c block: Require aligned image size to avoid assertion failure 2020-07-17 14:20:57 +02:00
blockdev-nbd.c
blockdev.c block: Add support to warn on backing file change without format 2020-07-14 15:18:59 +02:00
blockjob.c
bootdevice.c
Changelog
CODING_STYLE.rst
configure Block layer patches: 2020-07-17 14:58:13 +01:00
COPYING
COPYING.LIB
cpus-common.c
device_tree.c
disas.c
dma-helpers.c
exec-vary.c
exec.c
gdbstub.c qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
gitdm.config
hmp-commands-info.hx
hmp-commands.hx
iothread.c qom: Change object_get_canonical_path_component() not to malloc 2020-07-21 16:23:43 +02:00
job-qmp.c
job.c
Kconfig
Kconfig.host
LICENSE
MAINTAINERS docs/system: Document the arm virt board 2020-07-20 11:35:17 +01:00
Makefile Makefile: Remove config-devices.mak on "make clean" 2020-07-20 11:02:46 +01:00
Makefile.objs
Makefile.target
memory_ldst.inc.c
module-common.c
os-posix.c build: Check that mlockall() exists 2020-07-13 14:36:09 +01:00
os-win32.c
qdev-monitor.c
qemu-bridge-helper.c
qemu-edid.c
qemu-img-cmds.hx
qemu-img.c qemu-img resize: Require --shrink for shrinking all image formats 2020-07-17 14:20:57 +02:00
qemu-io-cmds.c
qemu-io.c
qemu-keymap.c
qemu-nbd.c
qemu-options-wrapper.h
qemu-options.h
qemu-options.hx ipmi: Fix a man page entry 2020-07-17 11:39:46 -05:00
qemu-seccomp.c
qemu-storage-daemon.c
qemu.nsi
qemu.sasl
README.rst
replication.c
replication.h
rules.mak
thunk.c
tpm.c
trace-events
VERSION Update version for v5.1.0-rc0 release 2020-07-15 19:08:07 +01:00
version.rc

===========
QEMU README
===========

QEMU is a generic and open source machine & userspace emulator and
virtualizer.

QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).

QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.

QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.

QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.


Building
========

QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:


.. code-block:: shell

  mkdir build
  cd build
  ../configure
  make

Additional information can also be found online via the QEMU website:

* `<https://qemu.org/Hosts/Linux>`_
* `<https://qemu.org/Hosts/Mac>`_
* `<https://qemu.org/Hosts/W32>`_


Submitting patches
==================

The QEMU source code is maintained under the GIT version control system.

.. code-block:: shell

   git clone https://git.qemu.org/git/qemu.git

When submitting patches, one common approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the CODING_STYLE.rst file.

Additional information on submitting patches can be found online via
the QEMU website

* `<https://qemu.org/Contribute/SubmitAPatch>`_
* `<https://qemu.org/Contribute/TrivialPatches>`_

The QEMU website is also maintained under source control.

.. code-block:: shell

  git clone https://git.qemu.org/git/qemu-web.git

* `<https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/>`_

A 'git-publish' utility was created to make above process less
cumbersome, and is highly recommended for making regular contributions,
or even just for sending consecutive patch series revisions. It also
requires a working 'git send-email' setup, and by default doesn't
automate everything, so you may want to go through the above steps
manually for once.

For installation instructions, please go to

*  `<https://github.com/stefanha/git-publish>`_

The workflow with 'git-publish' is:

.. code-block:: shell

  $ git checkout master -b my-feature
  $ # work on new commits, add your 'Signed-off-by' lines to each
  $ git publish

Your patch series will be sent and tagged as my-feature-v1 if you need to refer
back to it in the future.

Sending v2:

.. code-block:: shell

  $ git checkout my-feature # same topic branch
  $ # making changes to the commits (using 'git rebase', for example)
  $ git publish

Your patch series will be sent with 'v2' tag in the subject and the git tip
will be tagged as my-feature-v2.

Bug reporting
=============

The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:

* `<https://bugs.launchpad.net/qemu/>`_

If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via launchpad.

For additional information on bug reporting consult:

* `<https://qemu.org/Contribute/ReportABug>`_


Contact
=======

The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC

* `<mailto:qemu-devel@nongnu.org>`_
* `<https://lists.nongnu.org/mailman/listinfo/qemu-devel>`_
* #qemu on irc.oftc.net

Information on additional methods of contacting the community can be
found online via the QEMU website:

* `<https://qemu.org/Contribute/StartHere>`_