Xen Project 4.9 Acknowledgements

Note that the acknowledgements have been created based on 4.9.0-rc9, which is expected to be the final RC for Xen 4.9.0 (with the exception of some security fixes under embargo). If there is another release candidate, data needs to be updated.

Overview

As we have made significant changes to the xen source tree structure, we will count acknowledgements in line with RFC Xen 4.6 Acknowledgements.

The following table compares Xen 4.8 with Xen 4.9. We also cover changes to Xen only components in Linux, FreeBSD, NetBSD and QEMU in the "Drivers and Devices" column, which are primarily made by Xen Project developers. Note that the number is not part of the 4.9 Hypervisor Total.

Attribute	4.8 Hypervisor Total [ 1 ]	4.9 Hypervisor Total [ 1 ]	4.9 Hypervisor Core [ 2 ]	4.9 Hypervisor Other [ 3 ]	Drivers and Devices (other projects) [ 4 ]
Release Cycle	161 days 124 dev window/days [ 6 ] 5.3 months	203 days [ 7 ] 128 dev window/days [ 6 ] 6.3 months
Development Velocity
Changesets	1245	1549 (+19.6%)	1316	233	285
Series (=Features) [ 5 ]	575	481 (-19.5%)
Average Size of Feature	2.17	3.22 (+32.6%)
Changes / Day	7.7	7.6 (-0.9%)
Changes / Dev Day [ 6 ]	10.0	12.1 (+17.4%)
Features / Day [ 5 ]	3.6	2.4 (-51.9%)
Code Review Statistics
Review Comments [ 5 ]	6960	8349 (+16.6%)
Review Comments / Day [ 5 ]	43.6	41.1 (-6.0%)
Review Comments / Dev Day [ 6 ]	56.1	65.2 (+13.9%)
Comments / Series [ 5 ]	11.9	17.4 (+31.4%)
Code Churn
Lines Added	78899	82336 (+4.2%)	77190	5146	21558
Lines Removed	62325	47014 (-67.8%)	45320	1694	16705
Engagement
Individuals	68	85 (+20.9%)	83	10	79
Employers [ 8 ]	25	29 (+16.7%)	28	6	25

4.9 Hypervisor Only Code Contributions ^{[ 2 ]}

Breakdown by Individual

This table is sortable : please click on the icon besides the column header, to sort by a specific column.

Name	Lines Added	Lines Removed	Changesets
Adrian Pop	291	2	1
Al Stone	20	2	1
Alistair Francis	7	7	5
Andre Przywara	1809	26	11
Andrew Cooper	8219	7907	258
Andrii Anisov	1	0	1
Andy Lutomirski	7	5	1
Andy Shevchenko	39	0	1
Anshul Makkar	14	2	2
Anthony PERARD	17	2	4
Armando Vega	773	707	2
Artem Mygaiev	2	2	2
Bhavesh Davda	1	3	1
Bhupinder Thakur	66	16	2
Boris Ostrovsky	238	114	14
Cedric Bosdonnat	2094	1574	49
Chao Gao	167	80	9
Charles Arnold	1	1	1
Cristian-Bogdan Sirb	4	1	1
Daniel Kiper	1634	579	14
Dario Faggioli	1847	631	34
David Woodhouse	17	9	1
Doug Goldstein	14	40	4
Edgar E. Iglesias	5	41	5
Elena Ufimtseva	294	59	3
Eric DeVolder	85	15	7
Fatih Acar	21	13	2
Feng Wu	194	143	6
George Dunlap	170	73	9
Haozhong Zhang	464	345	24
He Chen	36	9	3
Ian Jackson	864	296	29
Igor Druzhinin	9	5	1
Jan Beulich	11008	4555	235
Jennifer Herbert	173	79	3
Joao Martins	10	3	1
Jonathan Davies	185	33	10
Joshua Otto	1	1	1
Juergen Gross	9785	8375	81
Julien Grall	666	407	47
Jun Sun	0	2	1
keios	5	5	1
Kevin Tian	0	1	1
Konrad Rzeszutek Wilk	188	109	8
Luca Miccio	2	1	1
Luwei Kang	47	8	3
Lv Zheng	126	0	1
Marek Marczykowski-Górecki	169	137	8
Mohit Gambhir	9	3	2
Norbert Manthey	3	3	2
Olaf Hering	1568	1	8
Oleksandr Andrushchenko	2098	27	4
Oleksandr Tyshchenko	28	26	3
Paul Durrant	3952	2186	31
Paul Lai	47	47	1
Peng Fan	22	11	1
Peter Große	3	3	2
Piotr Luc	1	0	1
Praveen Kumar	12	9	3
Punit Agrawal	7	5	1
Quan Xu	53	14	3
Razvan Cojocaru	451	153	7
Robin Lee	6	6	1
Roger Pau Monne	2980	1928	67
Ronald Rojas	1283	4	10
Ross Lagerwall	286	214	12
Sameer Goel	1	9	1
Sander Eikelenboom	1	1	1
Seraphime Kirkovski	2	2	2
Sergey Dyasli	377	54	13
Stefano Stabellini	2292	108	26
Suravee Suthikulpanit	207	133	3
Tamas K Lengyel	1278	974	5
Thomas Sanders	344	54	8
Tim Deegan	3	1	1
Venu Busireddy	23	2	2
Vijaya Kumar K	69	7	2
Vitaly Kuznetsov	41	17	3
Wei Chen	570	125	22
Wei Liu	16352	13506	139
Xiong Zhang	33	18	1
Yu Zhang	260	58	4
Zhang Chen	690	64	16
Zhongze Liu	49	10	2

4.9 Hypervisor Related Code Contributions ^{[ 3 ]}

Breakdown by Individual

Note that the table below does not cover contributions to Linux, NetBSD, FreeBSD, QEMU, libvirt and other related projects. It lists contributors to mini-os (formerly part of xen.git), osstest (our test code and test cases), raisin (a deployment and test tool), xtf.git and livepatch-build-tools (tools to builld livepatch payloads).

This table is sortable : please click on the icon besides the column header, to sort by a specific column.

Name	Lines Added	Lines Removed	Changesets
Andrew Cooper	2425	1131	50
Géza Gémes	427	29	16
Ian Jackson	1952	470	150
Jan Beulich	120	15	4
Mohit Gambhir	12	0	1
Paul Durrant	2	0	1
Ross Lagerwall	82	1	2
Simon Waterman	1	28	1
Stefano Stabellini	84	15	4
Wei Liu	41	5	4

Code Contributions to Xen Related Drivers and Devices in Linux, NetBSD, FreeBSD ^{[ 4 ]}

Breakdown by Individual

To Do: Insert data - will have to do this post the 4.9 release

This table is sortable : please click on the icon besides the column header, to sort by a specific column.

Name	Lines Added	Lines Removed	Changesets

4.9 Hypervisor Reviewers ^{[ 5 ]}

This table is sortable : please click on the icon besides the column header, to sort by a specific column. Note that in the table below, we only count review comments by community members other than comments by the author of a patch. We do not count replies and clarifications by the author of a patch that are made in response to review comments by others.

Name	Review Comments
119 others (less than 10 review comments each)	345
Alistair Francis	14
Andre Przywara	71
Andrew Cooper	792
Andy Lutomirski	11
Anthony Perard	13
Bhupinder Thakur	22
Boris Ostrovsky	286
Cedric Bosdonnat	11
Chao Gao	41
Dan Streetman	10
Daniel De Graaf	16
Daniel Kiper	100
Dario Faggioli	69
Doug Goldstein	82
Elena Reshetova	13
Fu Wei	10
George Dunlap	144
Géza Gémes	10
Greg Kurz	24
Grek KH	17
Haozhong Zhang	46
Ian Jackson	225
Jacob Shin	13
Jan Beulich	1634
Juergen Gross	222
Julien Grall	534
Kevin Tian	133
Konrad Wilk	179
Luis R. Rodriguez	74
Luwei Kang	11
Olaf Hering	14
Oleksandr Andrushchenko	64
Oleksandr Grytsov	11
Oleksandr Tyshchenko	24
Paul Durrant	172
Peter Zijlstra	14
Praveen Kumar	19
Quan Xu	24
Razvan Cojocaru	66
Roger Pau Monné	167
Ronald Rojas	21
Ross Lagerwall	11
Sergey Dyasli	17
Shanker Donthineni	11
Stefano Stabellini	628
Suravee Suthikulpanit	26
Tamas Lengyel	60
Thomas Garnier	28
Tim Deegan	68
Vijay Kilari	10
Waiman Long	13
Wei Liu	532
Yi Y Sun	119
Yu Zhang	51
Zhang Chen	18
Zhongze Liu	14

Footnotes

^{[ 1 ]} Includes the following repos: xen, mini-os, osstest, raisin, livepatch-build-tools, xtf
^{[ 2 ]} Includes the following repos: xen
^{[ 3 ]} Includes the following repos: mini-os, osstest, raisin, livepatch-build-tools, xtf
^{[ 4 ]} Includes commits to the following Xen specific directories of the following upstream projects: linux: arch/*/xen/ arch/*/include/asm/xen/ drivers/xen/ drivers/*/*xen* include/xen/ arch/*/pci/*xen* ; netbsd: sys/arch/xen; freebsd: sys/dev/xen/ sys/x86/xen sys/xen/; qemu: xen* hw/i386/xen hw/xenpv hw/*/xen* hw/xen include/*/xen*, xen windows pv drivers
^{[ 5 ]} This data was extracted from the Xen Project Code Review Dashboard
^{[ 6 ]} These are the days/months during which we were not in code freeze
^{[ 7 ]} Calculated using 4.9.0-rc9. Note that the code freeze for this release was 4 weeks longer than expected, due to several security issues being fixed towards the end of the release cycle and were held under embargo.
^{[ 8 ]} Only known employers are used. Unknown employers were discounted. Note that in [1] that clean-up did not happen