view Documentation/usb/CREDITS @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
line source
1 Credits for the Simple Linux USB Driver:
3 The following people have contributed to this code (in alphabetical
4 order by last name). I'm sure this list should be longer, its
5 difficult to maintain, add yourself with a patch if desired.
7 Georg Acher <acher@informatik.tu-muenchen.de>
8 David Brownell <dbrownell@users.sourceforge.net>
9 Alan Cox <alan@lxorguk.ukuu.org.uk>
10 Randy Dunlap <randy.dunlap@intel.com>
11 Johannes Erdfelt <johannes@erdfelt.com>
12 Deti Fliegl <deti@fliegl.de>
13 ham <ham@unsuave.com>
14 Bradley M Keryan <keryan@andrew.cmu.edu>
15 Greg Kroah-Hartman <greg@kroah.com>
16 Pavel Machek <pavel@suse.cz>
17 Paul Mackerras <paulus@cs.anu.edu.au>
18 Petko Manlolov <petkan@dce.bg>
19 David E. Nelson <dnelson@jump.net>
20 Vojtech Pavlik <vojtech@suse.cz>
21 Bill Ryder <bryder@sgi.com>
22 Thomas Sailer <sailer@ife.ee.ethz.ch>
23 Gregory P. Smith <greg@electricrain.com>
24 Linus Torvalds <torvalds@osdl.org>
25 Roman Weissgaerber <weissg@vienna.at>
26 <Kazuki.Yasumatsu@fujixerox.co.jp>
28 Special thanks to:
30 Inaky Perez Gonzalez <inaky@peloncho.fis.ucm.es> for starting the
31 Linux USB driver effort and writing much of the larger uusbd driver.
32 Much has been learned from that effort.
34 The NetBSD & FreeBSD USB developers. For being on the Linux USB list
35 and offering suggestions and sharing implementation experiences.
37 Additional thanks to the following companies and people for donations
38 of hardware, support, time and development (this is from the original
39 THANKS file in Inaky's driver):
41 The following corporations have helped us in the development
42 of Linux USB / UUSBD:
44 - 3Com GmbH for donating a ISDN Pro TA and supporting me
45 in technical questions and with test equipment. I'd never
46 expect such a great help.
48 - USAR Systems provided us with one of their excellent USB
49 Evaluation Kits. It allows us to test the Linux-USB driver
50 for compliance with the latest USB specification. USAR
51 Systems recognized the importance of an up-to-date open
52 Operating System and supports this project with
53 Hardware. Thanks!.
55 - Thanks to Intel Corporation for their precious help.
57 - We teamed up with Cherry to make Linux the first OS with
58 built-in USB support. Cherry is one of the biggest keyboard
59 makers in the world.
61 - CMD Technology, Inc. sponsored us kindly donating a CSA-6700
62 PCI-to-USB Controller Board to test the OHCI implementation.
64 - Due to their support to us, Keytronic can be sure that they
65 will sell keyboards to some of the 3 million (at least)
66 Linux users.
68 - Many thanks to ing büro h doran [http://www.ibhdoran.com]!
69 It was almost impossible to get a PC backplate USB connector
70 for the motherboard here at Europe (mine, home-made, was
71 quite lousy :). Now I know where to acquire nice USB stuff!
73 - Genius Germany donated a USB mouse to test the mouse boot
74 protocol. They've also donated a F-23 digital joystick and a
75 NetMouse Pro. Thanks!
77 - AVM GmbH Berlin is supporting the development of the Linux
78 USB driver for the AVM ISDN Controller B1 USB. AVM is a
79 leading manufacturer for active and passive ISDN Controllers
80 and CAPI 2.0-based software. The active design of the AVM B1
81 is open for all OS platforms, including Linux.
83 - Thanks to Y-E Data, Inc. for donating their FlashBuster-U
84 USB Floppy Disk Drive, so we could test the bulk transfer
85 code.
87 - Many thanks to Logitech for contributing a three axis USB
88 mouse.
90 Logitech designs, manufactures and markets
91 Human Interface Devices, having a long history and
92 experience in making devices such as keyboards, mice,
93 trackballs, cameras, loudspeakers and control devices for
94 gaming and professional use.
96 Being a recognized vendor and seller for all these devices,
97 they have donated USB mice, a joystick and a scanner, as a
98 way to acknowledge the importance of Linux and to allow
99 Logitech customers to enjoy support in their favorite
100 operating systems and all Linux users to use Logitech and
101 other USB hardware.
103 Logitech is official sponsor of the Linux Conference on
104 Feb. 11th 1999 in Vienna, where we'll will present the
105 current state of the Linux USB effort.
107 - CATC has provided means to uncover dark corners of the UHCI
108 inner workings with a USB Inspector.
110 - Thanks to Entrega for providing PCI to USB cards, hubs and
111 converter products for development.
113 - Thanks to ConnectTech for providing a WhiteHEAT usb to
114 serial converter, and the documentation for the device to
115 allow a driver to be written.
117 - Thanks to ADMtek for providing Pegasus and Pegasus II
118 evaluation boards, specs and valuable advices during
119 the driver development.
121 And thanks go to (hey! in no particular order :)
123 - Oren Tirosh <orenti@hishome.net>, for standing so patiently
124 all my doubts'bout USB and giving lots of cool ideas.
126 - Jochen Karrer <karrer@wpfd25.physik.uni-wuerzburg.de>, for
127 pointing out mortal bugs and giving advice.
129 - Edmund Humemberger <ed@atnet.at>, for it's great work on
130 public relationships and general management stuff for the
131 Linux-USB effort.
133 - Alberto Menegazzi <flash@flash.iol.it> is starting the
134 documentation for the UUSBD. Go for it!
136 - Ric Klaren <ia_ric@cs.utwente.nl> for doing nice
137 introductory documents (competing with Alberto's :).
139 - Christian Groessler <cpg@aladdin.de>, for it's help on those
140 itchy bits ... :)
142 - Paul MacKerras for polishing OHCI and pushing me harder for
143 the iMac support, giving improvements and enhancements.
145 - Fernando Herrera <fherrera@eurielec.etsit.upm.es> has taken
146 charge of composing, maintaining and feeding the
147 long-awaited, unique and marvelous UUSBD FAQ! Tadaaaa!!!
149 - Rasca Gmelch <thron@gmx.de> has revived the raw driver and
150 pointed bugs, as well as started the uusbd-utils package.
152 - Peter Dettori <dettori@ozy.dec.com> is uncovering bugs like
153 crazy, as well as making cool suggestions, great :)
155 - All the Free Software and Linux community, the FSF & the GNU
156 project, the MIT X consortium, the TeX people ... everyone!
157 You know who you are!
159 - Big thanks to Richard Stallman for creating Emacs!
161 - The people at the linux-usb mailing list, for reading so
162 many messages :) Ok, no more kidding; for all your advises!
164 - All the people at the USB Implementors Forum for their
165 help and assistance.
167 - Nathan Myers <ncm@cantrip.org>, for his advice! (hope you
168 liked Cibeles' party).
170 - Linus Torvalds, for starting, developing and managing Linux.
172 - Mike Smith, Craig Keithley, Thierry Giron and Janet Schank
173 for convincing me USB Standard hubs are not that standard
174 and that's good to allow for vendor specific quirks on the
175 standard hub driver.