ia64/linux-2.6.18-xen.hg

view arch/sparc64/Makefile @ 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 # $Id: Makefile,v 1.52 2002/02/09 19:49:31 davem Exp $
2 # sparc64/Makefile
3 #
4 # Makefile for the architecture dependent flags and dependencies on the
5 # 64-bit Sparc.
6 #
7 # Copyright (C) 1996,1998 David S. Miller (davem@caip.rutgers.edu)
8 # Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz)
9 #
11 CHECKFLAGS += -D__sparc__ -D__sparc_v9__ -m64
13 CPPFLAGS_vmlinux.lds += -Usparc
15 CC := $(shell if $(CC) -m64 -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo $(CC); else echo sparc64-linux-gcc; fi )
17 NEW_GCC := $(call cc-option-yn, -m64 -mcmodel=medlow)
18 NEW_GAS := $(shell if $(LD) -V 2>&1 | grep 'elf64_sparc' > /dev/null; then echo y; else echo n; fi)
19 UNDECLARED_REGS := $(shell if $(CC) -c -x assembler /dev/null -Wa,--help | grep undeclared-regs > /dev/null; then echo y; else echo n; fi; )
21 export NEW_GCC
23 ifneq ($(NEW_GAS),y)
24 AS = sparc64-linux-as
25 LD = sparc64-linux-ld
26 NM = sparc64-linux-nm
27 AR = sparc64-linux-ar
28 RANLIB = sparc64-linux-ranlib
29 else
30 AS := $(AS) -64
31 LDFLAGS := -m elf64_sparc
32 endif
34 ifneq ($(UNDECLARED_REGS),y)
35 CC_UNDECL =
36 else
37 CC_UNDECL = -Wa,--undeclared-regs
38 AS := $(AS) --undeclared-regs
39 endif
41 ifneq ($(NEW_GCC),y)
42 CFLAGS := $(CFLAGS) -pipe -mno-fpu -mtune=ultrasparc -mmedlow \
43 -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare
44 else
45 CFLAGS := $(CFLAGS) -m64 -pipe -mno-fpu -mcpu=ultrasparc -mcmodel=medlow \
46 -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare \
47 $(CC_UNDECL)
48 AFLAGS += -m64 -mcpu=ultrasparc $(CC_UNDECL)
49 endif
51 ifeq ($(CONFIG_MCOUNT),y)
52 CFLAGS := $(CFLAGS) -pg
53 endif
55 head-y := arch/sparc64/kernel/head.o arch/sparc64/kernel/init_task.o
57 core-y += arch/sparc64/kernel/ arch/sparc64/mm/
58 core-$(CONFIG_SOLARIS_EMUL) += arch/sparc64/solaris/
59 core-y += arch/sparc64/math-emu/
60 libs-y += arch/sparc64/prom/ arch/sparc64/lib/
62 # FIXME: is drivers- right?
63 drivers-$(CONFIG_OPROFILE) += arch/sparc64/oprofile/
65 boot := arch/sparc64/boot
67 image tftpboot.img vmlinux.aout: vmlinux
68 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
70 archclean:
71 $(Q)$(MAKE) $(clean)=$(boot)
73 define archhelp
74 echo '* vmlinux - Standard sparc64 kernel'
75 echo ' vmlinux.aout - a.out kernel for sparc64'
76 echo ' tftpboot.img - Image prepared for tftp'
77 endef