ia64/linux-2.6.18-xen.hg

view drivers/atm/idt77105.h @ 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 /* drivers/atm/idt77105.h - IDT77105 (PHY) declarations */
3 /* Written 1999 by Greg Banks, NEC Australia <gnb@linuxfan.com>. Based on suni.h */
6 #ifndef DRIVER_ATM_IDT77105_H
7 #define DRIVER_ATM_IDT77105_H
9 #include <linux/atmdev.h>
10 #include <linux/atmioc.h>
13 /* IDT77105 registers */
15 #define IDT77105_MCR 0x0 /* Master Control Register */
16 #define IDT77105_ISTAT 0x1 /* Interrupt Status */
17 #define IDT77105_DIAG 0x2 /* Diagnostic Control */
18 #define IDT77105_LEDHEC 0x3 /* LED Driver & HEC Status/Control */
19 #define IDT77105_CTRLO 0x4 /* Low Byte Counter Register */
20 #define IDT77105_CTRHI 0x5 /* High Byte Counter Register */
21 #define IDT77105_CTRSEL 0x6 /* Counter Register Read Select */
23 /* IDT77105 register values */
25 /* MCR */
26 #define IDT77105_MCR_UPLO 0x80 /* R/W, User Prog'le Output Latch */
27 #define IDT77105_MCR_DREC 0x40 /* R/W, Discard Receive Error Cells */
28 #define IDT77105_MCR_ECEIO 0x20 /* R/W, Enable Cell Error Interrupts
29 * Only */
30 #define IDT77105_MCR_TDPC 0x10 /* R/W, Transmit Data Parity Check */
31 #define IDT77105_MCR_DRIC 0x08 /* R/W, Discard Received Idle Cells */
32 #define IDT77105_MCR_HALTTX 0x04 /* R/W, Halt Tx */
33 #define IDT77105_MCR_UMODE 0x02 /* R/W, Utopia (cell/byte) Mode */
34 #define IDT77105_MCR_EIP 0x01 /* R/W, Enable Interrupt Pin */
36 /* ISTAT */
37 #define IDT77105_ISTAT_GOODSIG 0x40 /* R, Good Signal Bit */
38 #define IDT77105_ISTAT_HECERR 0x20 /* sticky, HEC Error*/
39 #define IDT77105_ISTAT_SCR 0x10 /* sticky, Short Cell Received */
40 #define IDT77105_ISTAT_TPE 0x08 /* sticky, Transmit Parity Error */
41 #define IDT77105_ISTAT_RSCC 0x04 /* sticky, Rx Signal Condition Change */
42 #define IDT77105_ISTAT_RSE 0x02 /* sticky, Rx Symbol Error */
43 #define IDT77105_ISTAT_RFO 0x01 /* sticky, Rx FIFO Overrun */
45 /* DIAG */
46 #define IDT77105_DIAG_FTD 0x80 /* R/W, Force TxClav deassert */
47 #define IDT77105_DIAG_ROS 0x40 /* R/W, RxClav operation select */
48 #define IDT77105_DIAG_MPCS 0x20 /* R/W, Multi-PHY config'n select */
49 #define IDT77105_DIAG_RFLUSH 0x10 /* R/W, clear receive FIFO */
50 #define IDT77105_DIAG_ITPE 0x08 /* R/W, Insert Tx payload error */
51 #define IDT77105_DIAG_ITHE 0x04 /* R/W, Insert Tx HEC error */
52 #define IDT77105_DIAG_UMODE 0x02 /* R/W, Utopia (cell/byte) Mode */
53 #define IDT77105_DIAG_LCMASK 0x03 /* R/W, Loopback Control */
55 #define IDT77105_DIAG_LC_NORMAL 0x00 /* Receive from network */
56 #define IDT77105_DIAG_LC_PHY_LOOPBACK 0x02
57 #define IDT77105_DIAG_LC_LINE_LOOPBACK 0x03
59 /* LEDHEC */
60 #define IDT77105_LEDHEC_DRHC 0x40 /* R/W, Disable Rx HEC check */
61 #define IDT77105_LEDHEC_DTHC 0x20 /* R/W, Disable Tx HEC calculation */
62 #define IDT77105_LEDHEC_RPWMASK 0x18 /* R/W, RxRef pulse width select */
63 #define IDT77105_LEDHEC_TFS 0x04 /* R, Tx FIFO Status (1=empty) */
64 #define IDT77105_LEDHEC_TLS 0x02 /* R, Tx LED Status (1=lit) */
65 #define IDT77105_LEDHEC_RLS 0x01 /* R, Rx LED Status (1=lit) */
67 #define IDT77105_LEDHEC_RPW_1 0x00 /* RxRef active for 1 RxClk cycle */
68 #define IDT77105_LEDHEC_RPW_2 0x08 /* RxRef active for 2 RxClk cycle */
69 #define IDT77105_LEDHEC_RPW_4 0x10 /* RxRef active for 4 RxClk cycle */
70 #define IDT77105_LEDHEC_RPW_8 0x18 /* RxRef active for 8 RxClk cycle */
72 /* CTRSEL */
73 #define IDT77105_CTRSEL_SEC 0x08 /* W, Symbol Error Counter */
74 #define IDT77105_CTRSEL_TCC 0x04 /* W, Tx Cell Counter */
75 #define IDT77105_CTRSEL_RCC 0x02 /* W, Rx Cell Counter */
76 #define IDT77105_CTRSEL_RHEC 0x01 /* W, Rx HEC Error Counter */
78 #ifdef __KERNEL__
79 int idt77105_init(struct atm_dev *dev);
80 #endif
82 /*
83 * Tunable parameters
84 */
86 /* Time between samples of the hardware cell counters. Should be <= 1 sec */
87 #define IDT77105_STATS_TIMER_PERIOD (HZ)
88 /* Time between checks to see if the signal has been found again */
89 #define IDT77105_RESTART_TIMER_PERIOD (5 * HZ)
91 #endif