ia64/linux-2.6.18-xen.hg

view scripts/Makefile.clean @ 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 # Cleaning up
3 # ==========================================================================
5 src := $(obj)
7 PHONY := __clean
8 __clean:
10 # Shorthand for $(Q)$(MAKE) scripts/Makefile.clean obj=dir
11 # Usage:
12 # $(Q)$(MAKE) $(clean)=dir
13 clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj
15 # The filename Kbuild has precedence over Makefile
16 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
17 include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile)
19 # Figure out what we need to build from the various variables
20 # ==========================================================================
22 __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
23 subdir-y += $(__subdir-y)
24 __subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
25 subdir-m += $(__subdir-m)
26 __subdir-n := $(patsubst %/,%,$(filter %/, $(obj-n)))
27 subdir-n += $(__subdir-n)
28 __subdir- := $(patsubst %/,%,$(filter %/, $(obj-)))
29 subdir- += $(__subdir-)
31 # Subdirectories we need to descend into
33 subdir-ym := $(sort $(subdir-y) $(subdir-m))
34 subdir-ymn := $(sort $(subdir-ym) $(subdir-n) $(subdir-))
36 # Add subdir path
38 subdir-ymn := $(addprefix $(obj)/,$(subdir-ymn))
40 # build a list of files to remove, usually releative to the current
41 # directory
43 __clean-files := $(extra-y) $(EXTRA_TARGETS) $(always) \
44 $(targets) $(clean-files) \
45 $(host-progs) \
46 $(hostprogs-y) $(hostprogs-m) $(hostprogs-)
48 # as clean-files is given relative to the current directory, this adds
49 # a $(obj) prefix, except for absolute paths
51 __clean-files := $(wildcard \
52 $(addprefix $(obj)/, $(filter-out /%, $(__clean-files))) \
53 $(filter /%, $(__clean-files)))
55 # as clean-dirs is given relative to the current directory, this adds
56 # a $(obj) prefix, except for absolute paths
58 __clean-dirs := $(wildcard \
59 $(addprefix $(obj)/, $(filter-out /%, $(clean-dirs))) \
60 $(filter /%, $(clean-dirs)))
62 # ==========================================================================
64 quiet_cmd_clean = CLEAN $(obj)
65 cmd_clean = rm -f $(__clean-files)
66 quiet_cmd_cleandir = CLEAN $(__clean-dirs)
67 cmd_cleandir = rm -rf $(__clean-dirs)
70 __clean: $(subdir-ymn)
71 ifneq ($(strip $(__clean-files)),)
72 +$(call cmd,clean)
73 endif
74 ifneq ($(strip $(__clean-dirs)),)
75 +$(call cmd,cleandir)
76 endif
77 ifneq ($(strip $(clean-rule)),)
78 +$(clean-rule)
79 endif
80 @:
83 # ===========================================================================
84 # Generic stuff
85 # ===========================================================================
87 # Descending
88 # ---------------------------------------------------------------------------
90 PHONY += $(subdir-ymn)
91 $(subdir-ymn):
92 $(Q)$(MAKE) $(clean)=$@
94 # If quiet is set, only print short version of command
96 cmd = @$(if $($(quiet)cmd_$(1)),echo ' $($(quiet)cmd_$(1))' &&) $(cmd_$(1))
99 # Declare the contents of the .PHONY variable as phony. We keep that
100 # information in a variable se we can use it in if_changed and friends.
102 .PHONY: $(PHONY)