ia64/linux-2.6.18-xen.hg

view Documentation/networking/skfp.txt @ 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
children
line source
1 (C)Copyright 1998-2000 SysKonnect,
2 ===========================================================================
4 skfp.txt created 11-May-2000
6 Readme File for skfp.o v2.06
9 This file contains
10 (1) OVERVIEW
11 (2) SUPPORTED ADAPTERS
12 (3) GENERAL INFORMATION
13 (4) INSTALLATION
14 (5) INCLUSION OF THE ADAPTER IN SYSTEM START
15 (6) TROUBLESHOOTING
16 (7) FUNCTION OF THE ADAPTER LEDS
17 (8) HISTORY
19 ===========================================================================
23 (1) OVERVIEW
24 ============
26 This README explains how to use the driver 'skfp' for Linux with your
27 network adapter.
29 Chapter 2: Contains a list of all network adapters that are supported by
30 this driver.
32 Chapter 3: Gives some general information.
34 Chapter 4: Describes common problems and solutions.
36 Chapter 5: Shows the changed functionality of the adapter LEDs.
38 Chapter 6: History of development.
40 ***
43 (2) SUPPORTED ADAPTERS
44 ======================
46 The network driver 'skfp' supports the following network adapters:
47 SysKonnect adapters:
48 - SK-5521 (SK-NET FDDI-UP)
49 - SK-5522 (SK-NET FDDI-UP DAS)
50 - SK-5541 (SK-NET FDDI-FP)
51 - SK-5543 (SK-NET FDDI-LP)
52 - SK-5544 (SK-NET FDDI-LP DAS)
53 - SK-5821 (SK-NET FDDI-UP64)
54 - SK-5822 (SK-NET FDDI-UP64 DAS)
55 - SK-5841 (SK-NET FDDI-FP64)
56 - SK-5843 (SK-NET FDDI-LP64)
57 - SK-5844 (SK-NET FDDI-LP64 DAS)
58 Compaq adapters (not tested):
59 - Netelligent 100 FDDI DAS Fibre SC
60 - Netelligent 100 FDDI SAS Fibre SC
61 - Netelligent 100 FDDI DAS UTP
62 - Netelligent 100 FDDI SAS UTP
63 - Netelligent 100 FDDI SAS Fibre MIC
64 ***
67 (3) GENERAL INFORMATION
68 =======================
70 From v2.01 on, the driver is integrated in the linux kernel sources.
71 Therefor, the installation is the same as for any other adapter
72 supported by the kernel.
73 Refer to the manual of your distribution about the installation
74 of network adapters.
75 Makes my life much easier :-)
76 ***
79 (4) TROUBLESHOOTING
80 ===================
82 If you run into problems during installation, check those items:
84 Problem: The FDDI adapter can not be found by the driver.
85 Reason: Look in /proc/pci for the following entry:
86 'FDDI network controller: SysKonnect SK-FDDI-PCI ...'
87 If this entry exists, then the FDDI adapter has been
88 found by the system and should be able to be used.
89 If this entry does not exist or if the file '/proc/pci'
90 is not there, then you may have a hardware problem or PCI
91 support may not be enabled in your kernel.
92 The adapter can be checked using the diagnostic program
93 which is available from the SysKonnect web site:
94 www.syskonnect.de
95 Some COMPAQ machines have a problem with PCI under
96 Linux. This is described in the 'PCI howto' document
97 (included in some distributions or available from the
98 www, e.g. at 'www.linux.org') and no workaround is available.
100 Problem: You want to use your computer as a router between
101 multiple IP subnetworks (using multiple adapters), but
102 you can not reach computers in other subnetworks.
103 Reason: Either the router's kernel is not configured for IP
104 forwarding or there is a problem with the routing table
105 and gateway configuration in at least one of the
106 computers.
108 If your problem is not listed here, please contact our
109 technical support for help.
110 You can send email to:
111 linux@syskonnect.de
112 When contacting our technical support,
113 please ensure that the following information is available:
114 - System Manufacturer and Model
115 - Boards in your system
116 - Distribution
117 - Kernel version
119 ***
122 (5) FUNCTION OF THE ADAPTER LEDS
123 ================================
125 The functionality of the LED's on the FDDI network adapters was
126 changed in SMT version v2.82. With this new SMT version, the yellow
127 LED works as a ring operational indicator. An active yellow LED
128 indicates that the ring is down. The green LED on the adapter now
129 works as a link indicator where an active GREEN LED indicates that
130 the respective port has a physical connection.
132 With versions of SMT prior to v2.82 a ring up was indicated if the
133 yellow LED was off while the green LED(s) showed the connection
134 status of the adapter. During a ring down the green LED was off and
135 the yellow LED was on.
137 All implementations indicate that a driver is not loaded if
138 all LEDs are off.
140 ***
143 (6) HISTORY
144 ===========
146 v2.06 (20000511) (In-Kernel version)
147 New features:
148 - 64 bit support
149 - new pci dma interface
150 - in kernel 2.3.99
152 v2.05 (20000217) (In-Kernel version)
153 New features:
154 - Changes for 2.3.45 kernel
156 v2.04 (20000207) (Standalone version)
157 New features:
158 - Added rx/tx byte counter
160 v2.03 (20000111) (Standalone version)
161 Problems fixed:
162 - Fixed printk statements from v2.02
164 v2.02 (991215) (Standalone version)
165 Problems fixed:
166 - Removed unnecessary output
167 - Fixed path for "printver.sh" in makefile
169 v2.01 (991122) (In-Kernel version)
170 New features:
171 - Integration in Linux kernel sources
172 - Support for memory mapped I/O.
174 v2.00 (991112)
175 New features:
176 - Full source released under GPL
178 v1.05 (991023)
179 Problems fixed:
180 - Compilation with kernel version 2.2.13 failed
182 v1.04 (990427)
183 Changes:
184 - New SMT module included, changing LED functionality
185 Problems fixed:
186 - Synchronization on SMP machines was buggy
188 v1.03 (990325)
189 Problems fixed:
190 - Interrupt routing on SMP machines could be incorrect
192 v1.02 (990310)
193 New features:
194 - Support for kernel versions 2.2.x added
195 - Kernel patch instead of private duplicate of kernel functions
197 v1.01 (980812)
198 Problems fixed:
199 Connection hangup with telnet
200 Slow telnet connection
202 v1.00 beta 01 (980507)
203 New features:
204 None.
205 Problems fixed:
206 None.
207 Known limitations:
208 - tar archive instead of standard package format (rpm).
209 - FDDI statistic is empty.
210 - not tested with 2.1.xx kernels
211 - integration in kernel not tested
212 - not tested simultaneously with FDDI adapters from other vendors.
213 - only X86 processors supported.
214 - SBA (Synchronous Bandwidth Allocator) parameters can
215 not be configured.
216 - does not work on some COMPAQ machines. See the PCI howto
217 document for details about this problem.
218 - data corruption with kernel versions below 2.0.33.
220 *** End of information file ***