ia64/linux-2.6.18-xen.hg

view Documentation/networking/tms380tr.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 Text file for the Linux SysKonnect Token Ring ISA/PCI Adapter Driver.
2 Text file by: Jay Schulist <jschlst@samba.org>
4 The Linux SysKonnect Token Ring driver works with the SysKonnect TR4/16(+) ISA,
5 SysKonnect TR4/16(+) PCI, SysKonnect TR4/16 PCI, and older revisions of the
6 SK NET TR4/16 ISA card.
8 Latest information on this driver can be obtained on the Linux-SNA WWW site.
9 Please point your browser to:
10 http://www.linux-sna.org
12 Many thanks to Christoph Goos for his excellent work on this driver and
13 SysKonnect for donating the adapters to Linux-SNA for the testing and
14 maintenance of this device driver.
16 Important information to be noted:
17 1. Adapters can be slow to open (~20 secs) and close (~5 secs), please be
18 patient.
19 2. This driver works very well when autoprobing for adapters. Why even
20 think about those nasty io/int/dma settings of modprobe when the driver
21 will do it all for you!
23 This driver is rather simple to use. Select Y to Token Ring adapter support
24 in the kernel configuration. A choice for SysKonnect Token Ring adapters will
25 appear. This drives supports all SysKonnect ISA and PCI adapters. Choose this
26 option. I personally recommend compiling the driver as a module (M), but if you
27 you would like to compile it staticly answer Y instead.
29 This driver supports multiple adapters without the need to load multiple copies
30 of the driver. You should be able to load up to 7 adapters without any kernel
31 modifications, if you are in need of more please contact the maintainer of this
32 driver.
34 Load the driver either by lilo/loadlin or as a module. When a module using the
35 following command will suffice for most:
37 # modprobe sktr
39 This will produce output similar to the following: (Output is user specific)
41 sktr.c: v1.01 08/29/97 by Christoph Goos
42 tr0: SK NET TR 4/16 PCI found at 0x6100, using IRQ 17.
43 tr1: SK NET TR 4/16 PCI found at 0x6200, using IRQ 16.
44 tr2: SK NET TR 4/16 ISA found at 0xa20, using IRQ 10 and DMA 5.
46 Now just setup the device via ifconfig and set and routes you may have. After
47 this you are ready to start sending some tokens.
49 Errata:
50 For anyone wondering where to pick up the SysKonnect adapters please browse
51 to http://www.syskonnect.com
53 This driver is under the GNU General Public License. Its Firmware image is
54 included as an initialized C-array and is licensed by SysKonnect to the Linux
55 users of this driver. However no warranty about its fitness is expressed or
56 implied by SysKonnect.
58 Below find attached the setting for the SK NET TR 4/16 ISA adapters
59 -------------------------------------------------------------------
61 ***************************
62 *** C O N T E N T S ***
63 ***************************
65 1) Location of DIP-Switch W1
66 2) Default settings
67 3) DIP-Switch W1 description
70 ==============================================================
71 CHAPTER 1 LOCATION OF DIP-SWITCH
72 ==============================================================
74 U컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴
75 U컴컴컴 U컴컴커 U컴커
76 A컴컴컴U W1 A컴컴훃 U컴컴
77 U컴컴컴 U컴탓
78 A컴컴컴U U컴컴컴컴컴커 A컴컴U
79 U컴컴컴 U컴커 A컴훃 A컴휱
80 A컴컴컴U TMS380C26
81 U컴컴컴 A컴훃 A커
82 A컴컴컴U
83 A컴컴컴컴컴훃
85 A훃
90 A컴컴컴컴컴컴A컴컴컴컴컴컴컴컴A컴A컴컴컴컴컴컴컴컴컴컴컴횫컴컴컴컴훃
91 A컴컴컴컴컴컴컴컴U A컴컴컴컴컴컴컴컴컴컴컴훃
93 ==============================================================
94 CHAPTER 2 DEFAULT SETTINGS
95 ==============================================================
97 W1 1 2 3 4 5 6 7 8
98 +------------------------------+
99 | ON X |
100 | OFF X X X X X X X |
101 +------------------------------+
103 W1.1 = ON Adapter drives address lines SA17..19
104 W1.2 - 1.5 = OFF BootROM disabled
105 W1.6 - 1.8 = OFF I/O address 0A20h
107 ==============================================================
108 CHAPTER 3 DIP SWITCH W1 DESCRIPTION
109 ==============================================================
111 U컴횫컴횫컴횫컴횫컴횫컴횫컴횫컴커 ON
112 1 2 3 4 5 6 7 8
113 A컴횫컴횫컴횫컴횫컴횫컴횫컴횫컴훃 OFF
114 |AD | BootROM Addr. | I/O |
115 +-+-+-------+-------+-----+-----+
116 | | |
117 | | +------ 6 7 8
118 | | ON ON ON 1900h
119 | | ON ON OFF 0900h
120 | | ON OFF ON 1980h
121 | | ON OFF OFF 0980h
122 | | OFF ON ON 1b20h
123 | | OFF ON OFF 0b20h
124 | | OFF OFF ON 1a20h
125 | | OFF OFF OFF 0a20h (+)
126 | |
127 | |
128 | +-------- 2 3 4 5
129 | OFF x x x disabled (+)
130 | ON ON ON ON C0000
131 | ON ON ON OFF C4000
132 | ON ON OFF ON C8000
133 | ON ON OFF OFF CC000
134 | ON OFF ON ON D0000
135 | ON OFF ON OFF D4000
136 | ON OFF OFF ON D8000
137 | ON OFF OFF OFF DC000
138 |
139 |
140 +----- 1
141 OFF adapter does NOT drive SA<17..19>
142 ON adapter drives SA<17..19> (+)
145 (+) means default setting
147 ********************************