ia64/linux-2.6.18-xen.hg

view scripts/export_report.pl @ 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 #!/usr/bin/perl -w
2 #
3 # (C) Copyright IBM Corporation 2006.
4 # Released under GPL v2.
5 # Author : Ram Pai (linuxram@us.ibm.com)
6 #
7 # Usage: export_report.pl -k Module.symvers [-o report_file ] -f *.mod.c
8 #
10 use Getopt::Std;
11 use strict;
13 sub numerically {
14 my $no1 = (split /\s+/, $a)[1];
15 my $no2 = (split /\s+/, $b)[1];
16 return $no1 <=> $no2;
17 }
19 sub alphabetically {
20 my ($module1, $value1) = @{$a};
21 my ($module2, $value2) = @{$b};
22 return $value1 <=> $value2 || $module2 cmp $module1;
23 }
25 sub print_depends_on {
26 my ($href) = @_;
27 print "\n";
28 while (my ($mod, $list) = each %$href) {
29 print "\t$mod:\n";
30 foreach my $sym (sort numerically @{$list}) {
31 my ($symbol, $no) = split /\s+/, $sym;
32 printf("\t\t%-25s\t%-25d\n", $symbol, $no);
33 }
34 print "\n";
35 }
36 print "\n";
37 print "~"x80 , "\n";
38 }
40 sub usage {
41 print "Usage: @_ -h -k Module.symvers [ -o outputfile ] \n",
42 "\t-f: treat all the non-option argument as .mod.c files. ",
43 "Recommend using this as the last option\n",
44 "\t-h: print detailed help\n",
45 "\t-k: the path to Module.symvers file. By default uses ",
46 "the file from the current directory\n",
47 "\t-o outputfile: output the report to outputfile\n";
48 exit 0;
49 }
51 sub collectcfiles {
52 my @file = `cat .tmp_versions/*.mod | grep '.*\.ko\$'`;
53 @file = grep {s/\.ko/.mod.c/} @file;
54 chomp @file;
55 return @file;
56 }
58 my (%SYMBOL, %MODULE, %opt, @allcfiles);
60 if (not getopts('hk:o:f',\%opt) or defined $opt{'h'}) {
61 usage($0);
62 }
64 if (defined $opt{'f'}) {
65 @allcfiles = @ARGV;
66 } else {
67 @allcfiles = collectcfiles();
68 }
70 if (not defined $opt{'k'}) {
71 $opt{'k'} = "Module.symvers";
72 }
74 unless (open(MODULE_SYMVERS, $opt{'k'})) {
75 die "Sorry, cannot open $opt{'k'}: $!\n";
76 }
78 if (defined $opt{'o'}) {
79 unless (open(OUTPUT_HANDLE, ">$opt{'o'}")) {
80 die "Sorry, cannot open $opt{'o'} $!\n";
81 }
82 select OUTPUT_HANDLE;
83 }
84 #
85 # collect all the symbols and their attributes from the
86 # Module.symvers file
87 #
88 while ( <MODULE_SYMVERS> ) {
89 chomp;
90 my (undef, $symbol, $module, $gpl) = split;
91 $SYMBOL { $symbol } = [ $module , "0" , $symbol, $gpl];
92 }
93 close(MODULE_SYMVERS);
95 #
96 # collect the usage count of each symbol.
97 #
98 foreach my $thismod (@allcfiles) {
99 unless (open(MODULE_MODULE, $thismod)) {
100 print "Sorry, cannot open $thismod: $!\n";
101 next;
102 }
103 my $state=0;
104 while ( <MODULE_MODULE> ) {
105 chomp;
106 if ($state eq 0) {
107 $state = 1 if ($_ =~ /static const struct modversion_info/);
108 next;
109 }
110 if ($state eq 1) {
111 $state = 2 if ($_ =~ /__attribute__\(\(section\("__versions"\)\)\)/);
112 next;
113 }
114 if ($state eq 2) {
115 if ( $_ !~ /0x[0-9a-f]{7,8},/ ) {
116 next;
117 }
118 my $sym = (split /([,"])/,)[4];
119 my ($module, $value, $symbol, $gpl) = @{$SYMBOL{$sym}};
120 $SYMBOL{ $sym } = [ $module, $value+1, $symbol, $gpl];
121 push(@{$MODULE{$thismod}} , $sym);
122 }
123 }
124 if ($state ne 2) {
125 print "WARNING:$thismod is not built with CONFIG_MODVERSION enabled\n";
126 }
127 close(MODULE_MODULE);
128 }
130 print "\tThis file reports the exported symbols usage patterns by in-tree\n",
131 "\t\t\t\tmodules\n";
132 printf("%s\n\n\n","x"x80);
133 printf("\t\t\t\tINDEX\n\n\n");
134 printf("SECTION 1: Usage counts of all exported symbols\n");
135 printf("SECTION 2: List of modules and the exported symbols they use\n");
136 printf("%s\n\n\n","x"x80);
137 printf("SECTION 1:\tThe exported symbols and their usage count\n\n");
138 printf("%-25s\t%-25s\t%-5s\t%-25s\n", "Symbol", "Module", "Usage count",
139 "export type");
141 #
142 # print the list of unused exported symbols
143 #
144 foreach my $list (sort alphabetically values(%SYMBOL)) {
145 my ($module, $value, $symbol, $gpl) = @{$list};
146 printf("%-25s\t%-25s\t%-10s\t", $symbol, $module, $value);
147 if (defined $gpl) {
148 printf("%-25s\n",$gpl);
149 } else {
150 printf("\n");
151 }
152 }
153 printf("%s\n\n\n","x"x80);
155 printf("SECTION 2:\n\tThis section reports export-symbol-usage of in-kernel
156 modules. Each module lists the modules, and the symbols from that module that
157 it uses. Each listed symbol reports the number of modules using it\n");
159 print "~"x80 , "\n";
160 while (my ($thismod, $list) = each %MODULE) {
161 my %depends;
162 $thismod =~ s/\.mod\.c/.ko/;
163 print "\t\t\t$thismod\n";
164 foreach my $symbol (@{$list}) {
165 my ($module, $value, undef, $gpl) = @{$SYMBOL{$symbol}};
166 push (@{$depends{"$module"}}, "$symbol $value");
167 }
168 print_depends_on(\%depends);
169 }