ia64/linux-2.6.18-xen.hg

view drivers/net/chelsio/espi.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 /*****************************************************************************
2 * *
3 * File: espi.h *
4 * $Revision: 1.7 $ *
5 * $Date: 2005/06/21 18:29:47 $ *
6 * Description: *
7 * part of the Chelsio 10Gb Ethernet Driver. *
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License, version 2, as *
11 * published by the Free Software Foundation. *
12 * *
13 * You should have received a copy of the GNU General Public License along *
14 * with this program; if not, write to the Free Software Foundation, Inc., *
15 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
16 * *
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED *
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF *
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. *
20 * *
21 * http://www.chelsio.com *
22 * *
23 * Copyright (c) 2003 - 2005 Chelsio Communications, Inc. *
24 * All rights reserved. *
25 * *
26 * Maintainers: maintainers@chelsio.com *
27 * *
28 * Authors: Dimitrios Michailidis <dm@chelsio.com> *
29 * Tina Yang <tainay@chelsio.com> *
30 * Felix Marti <felix@chelsio.com> *
31 * Scott Bardone <sbardone@chelsio.com> *
32 * Kurt Ottaway <kottaway@chelsio.com> *
33 * Frank DiMambro <frank@chelsio.com> *
34 * *
35 * History: *
36 * *
37 ****************************************************************************/
39 #ifndef _CXGB_ESPI_H_
40 #define _CXGB_ESPI_H_
42 #include "common.h"
44 struct espi_intr_counts {
45 unsigned int DIP4_err;
46 unsigned int rx_drops;
47 unsigned int tx_drops;
48 unsigned int rx_ovflw;
49 unsigned int parity_err;
50 unsigned int DIP2_parity_err;
51 };
53 struct peespi;
55 struct peespi *t1_espi_create(adapter_t *adapter);
56 void t1_espi_destroy(struct peespi *espi);
57 int t1_espi_init(struct peespi *espi, int mac_type, int nports);
59 void t1_espi_intr_enable(struct peespi *);
60 void t1_espi_intr_clear(struct peespi *);
61 void t1_espi_intr_disable(struct peespi *);
62 int t1_espi_intr_handler(struct peespi *);
63 const struct espi_intr_counts *t1_espi_get_intr_counts(struct peespi *espi);
65 void t1_espi_set_misc_ctrl(adapter_t *adapter, u32 val);
66 u32 t1_espi_get_mon(adapter_t *adapter, u32 addr, u8 wait);
68 #endif /* _CXGB_ESPI_H_ */