ia64/linux-2.6.18-xen.hg

view scripts/namespace.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 # namespace.pl. Mon Aug 30 2004
4 #
5 # Perform a name space analysis on the linux kernel.
6 #
7 # Copyright Keith Owens <kaos@ocs.com.au>. GPL.
8 #
9 # Invoke by changing directory to the top of the kernel object
10 # tree then namespace.pl, no parameters.
11 #
12 # Tuned for 2.1.x kernels with the new module handling, it will
13 # work with 2.0 kernels as well.
14 #
15 # Last change 2.6.9-rc1, adding support for separate source and object
16 # trees.
17 #
18 # The source must be compiled/assembled first, the object files
19 # are the primary input to this script. Incomplete or missing
20 # objects will result in a flawed analysis. Compile both vmlinux
21 # and modules.
22 #
23 # Even with complete objects, treat the result of the analysis
24 # with caution. Some external references are only used by
25 # certain architectures, others with certain combinations of
26 # configuration parameters. Ideally the source should include
27 # something like
28 #
29 # #ifndef CONFIG_...
30 # static
31 # #endif
32 # symbol_definition;
33 #
34 # so the symbols are defined as static unless a particular
35 # CONFIG_... requires it to be external.
36 #
37 # A symbol that is suffixed with '(export only)' has these properties
38 #
39 # * It is global.
40 # * It is marked EXPORT_SYMBOL or EXPORT_SYMBOL_GPL, either in the same
41 # source file or a different source file.
42 # * Given the current .config, nothing uses the symbol.
43 #
44 # The symbol is a candidate for conversion to static, plus removal of the
45 # export. But be careful that a different .config might use the symbol.
46 #
47 #
48 # Name space analysis and cleanup is an iterative process. You cannot
49 # expect to find all the problems in a single pass.
50 #
51 # * Identify possibly unnecessary global declarations, verify that they
52 # really are unnecessary and change them to static.
53 # * Compile and fix up gcc warnings about static, removing dead symbols
54 # as necessary.
55 # * make clean and rebuild with different configs (especially
56 # CONFIG_MODULES=n) to see which symbols are being defined when the
57 # config does not require them. These symbols bloat the kernel object
58 # for no good reason, which is frustrating for embedded systems.
59 # * Wrap config sensitive symbols in #ifdef CONFIG_foo, as long as the
60 # code does not get too ugly.
61 # * Repeat the name space analysis until you can live with with the
62 # result.
63 #
65 require 5; # at least perl 5
66 use strict;
67 use File::Find;
69 my $nm = ($ENV{'NM'} || "nm") . " -p";
70 my $objdump = ($ENV{'OBJDUMP'} || "objdump") . " -s -j .comment";
71 my $srctree = "";
72 my $objtree = "";
73 $srctree = "$ENV{'srctree'}/" if (exists($ENV{'srctree'}));
74 $objtree = "$ENV{'objtree'}/" if (exists($ENV{'objtree'}));
76 if ($#ARGV != -1) {
77 print STDERR "usage: $0 takes no parameters\n";
78 die("giving up\n");
79 }
81 my %nmdata = (); # nm data for each object
82 my %def = (); # all definitions for each name
83 my %ksymtab = (); # names that appear in __ksymtab_
84 my %ref = (); # $ref{$name} exists if there is a true external reference to $name
85 my %export = (); # $export{$name} exists if there is an EXPORT_... of $name
87 &find(\&linux_objects, '.'); # find the objects and do_nm on them
88 &list_multiply_defined();
89 &resolve_external_references();
90 &list_extra_externals();
92 exit(0);
94 sub linux_objects
95 {
96 # Select objects, ignoring objects which are only created by
97 # merging other objects. Also ignore all of modules, scripts
98 # and compressed. Most conglomerate objects are handled by do_nm,
99 # this list only contains the special cases. These include objects
100 # that are linked from just one other object and objects for which
101 # there is really no permanent source file.
102 my $basename = $_;
103 $_ = $File::Find::name;
104 s:^\./::;
105 if (/.*\.o$/ &&
106 ! (
107 m:/built-in.o$:
108 || m:arch/i386/kernel/vsyscall-syms.o$:
109 || m:arch/ia64/ia32/ia32.o$:
110 || m:arch/ia64/kernel/gate-syms.o$:
111 || m:arch/ia64/lib/__divdi3.o$:
112 || m:arch/ia64/lib/__divsi3.o$:
113 || m:arch/ia64/lib/__moddi3.o$:
114 || m:arch/ia64/lib/__modsi3.o$:
115 || m:arch/ia64/lib/__udivdi3.o$:
116 || m:arch/ia64/lib/__udivsi3.o$:
117 || m:arch/ia64/lib/__umoddi3.o$:
118 || m:arch/ia64/lib/__umodsi3.o$:
119 || m:arch/ia64/scripts/check_gas_for_hint.o$:
120 || m:arch/ia64/sn/kernel/xp.o$:
121 || m:boot/bbootsect.o$:
122 || m:boot/bsetup.o$:
123 || m:/bootsect.o$:
124 || m:/boot/setup.o$:
125 || m:/compressed/:
126 || m:drivers/cdrom/driver.o$:
127 || m:drivers/char/drm/tdfx_drv.o$:
128 || m:drivers/ide/ide-detect.o$:
129 || m:drivers/ide/pci/idedriver-pci.o$:
130 || m:drivers/media/media.o$:
131 || m:drivers/scsi/sd_mod.o$:
132 || m:drivers/video/video.o$:
133 || m:fs/devpts/devpts.o$:
134 || m:fs/exportfs/exportfs.o$:
135 || m:fs/hugetlbfs/hugetlbfs.o$:
136 || m:fs/msdos/msdos.o$:
137 || m:fs/nls/nls.o$:
138 || m:fs/ramfs/ramfs.o$:
139 || m:fs/romfs/romfs.o$:
140 || m:fs/vfat/vfat.o$:
141 || m:init/mounts.o$:
142 || m:^modules/:
143 || m:net/netlink/netlink.o$:
144 || m:net/sched/sched.o$:
145 || m:/piggy.o$:
146 || m:^scripts/:
147 || m:sound/.*/snd-:
148 || m:^.*/\.tmp_:
149 || m:^\.tmp_:
150 || m:/vmlinux-obj.o$:
151 )
152 ) {
153 do_nm($basename, $_);
154 }
155 $_ = $basename; # File::Find expects $_ untouched (undocumented)
156 }
158 sub do_nm
159 {
160 my ($basename, $fullname) = @_;
161 my ($source, $type, $name);
162 if (! -e $basename) {
163 printf STDERR "$basename does not exist\n";
164 return;
165 }
166 if ($fullname !~ /\.o$/) {
167 printf STDERR "$fullname is not an object file\n";
168 return;
169 }
170 ($source = $fullname) =~ s/\.o$//;
171 if (-e "$objtree$source.c" || -e "$objtree$source.S") {
172 $source = "$objtree$source";
173 } else {
174 $source = "$srctree$source";
175 }
176 if (! -e "$source.c" && ! -e "$source.S") {
177 # No obvious source, exclude the object if it is conglomerate
178 if (! open(OBJDUMPDATA, "$objdump $basename|")) {
179 printf STDERR "$objdump $fullname failed $!\n";
180 return;
181 }
182 my $comment;
183 while (<OBJDUMPDATA>) {
184 chomp();
185 if (/^In archive/) {
186 # Archives are always conglomerate
187 $comment = "GCC:GCC:";
188 last;
189 }
190 next if (! /^[ 0-9a-f]{5,} /);
191 $comment .= substr($_, 43);
192 }
193 close(OBJDUMPDATA);
194 if (!defined($comment) || $comment !~ /GCC\:.*GCC\:/m) {
195 printf STDERR "No source file found for $fullname\n";
196 }
197 return;
198 }
199 if (! open(NMDATA, "$nm $basename|")) {
200 printf STDERR "$nm $fullname failed $!\n";
201 return;
202 }
203 my @nmdata;
204 while (<NMDATA>) {
205 chop;
206 ($type, $name) = (split(/ +/, $_, 3))[1..2];
207 # Expected types
208 # A absolute symbol
209 # B weak external reference to data that has been resolved
210 # C global variable, uninitialised
211 # D global variable, initialised
212 # G global variable, initialised, small data section
213 # R global array, initialised
214 # S global variable, uninitialised, small bss
215 # T global label/procedure
216 # U external reference
217 # W weak external reference to text that has been resolved
218 # a assembler equate
219 # b static variable, uninitialised
220 # d static variable, initialised
221 # g static variable, initialised, small data section
222 # r static array, initialised
223 # s static variable, uninitialised, small bss
224 # t static label/procedures
225 # w weak external reference to text that has not been resolved
226 # ? undefined type, used a lot by modules
227 if ($type !~ /^[ABCDGRSTUWabdgrstw?]$/) {
228 printf STDERR "nm output for $fullname contains unknown type '$_'\n";
229 }
230 elsif ($name =~ /\./) {
231 # name with '.' is local static
232 }
233 else {
234 $type = 'R' if ($type eq '?'); # binutils replaced ? with R at one point
235 # binutils keeps changing the type for exported symbols, force it to R
236 $type = 'R' if ($name =~ /^__ksymtab/ || $name =~ /^__kstrtab/);
237 $name =~ s/_R[a-f0-9]{8}$//; # module versions adds this
238 if ($type =~ /[ABCDGRSTW]/ &&
239 $name ne 'init_module' &&
240 $name ne 'cleanup_module' &&
241 $name ne 'Using_Versions' &&
242 $name !~ /^Version_[0-9]+$/ &&
243 $name !~ /^__parm_/ &&
244 $name !~ /^__kstrtab/ &&
245 $name !~ /^__ksymtab/ &&
246 $name !~ /^__kcrctab_/ &&
247 $name !~ /^__exitcall_/ &&
248 $name !~ /^__initcall_/ &&
249 $name !~ /^__kdb_initcall_/ &&
250 $name !~ /^__kdb_exitcall_/ &&
251 $name !~ /^__module_/ &&
252 $name !~ /^__mod_/ &&
253 $name !~ /^__crc_/ &&
254 $name ne '__this_module' &&
255 $name ne 'kernel_version') {
256 if (!exists($def{$name})) {
257 $def{$name} = [];
258 }
259 push(@{$def{$name}}, $fullname);
260 }
261 push(@nmdata, "$type $name");
262 if ($name =~ /^__ksymtab_/) {
263 $name = substr($name, 10);
264 if (!exists($ksymtab{$name})) {
265 $ksymtab{$name} = [];
266 }
267 push(@{$ksymtab{$name}}, $fullname);
268 }
269 }
270 }
271 close(NMDATA);
272 if ($#nmdata < 0) {
273 if (
274 $fullname ne "lib/brlock.o"
275 && $fullname ne "lib/dec_and_lock.o"
276 && $fullname ne "fs/xfs/xfs_macros.o"
277 && $fullname ne "drivers/ide/ide-probe-mini.o"
278 && $fullname ne "usr/initramfs_data.o"
279 && $fullname ne "drivers/acpi/executer/exdump.o"
280 && $fullname ne "drivers/acpi/resources/rsdump.o"
281 && $fullname ne "drivers/acpi/namespace/nsdumpdv.o"
282 && $fullname ne "drivers/acpi/namespace/nsdump.o"
283 && $fullname ne "arch/ia64/sn/kernel/sn2/io.o"
284 && $fullname ne "arch/ia64/kernel/gate-data.o"
285 && $fullname ne "drivers/ieee1394/oui.o"
286 && $fullname ne "security/capability.o"
287 && $fullname ne "sound/core/wrappers.o"
288 && $fullname ne "fs/ntfs/sysctl.o"
289 && $fullname ne "fs/jfs/jfs_debug.o"
290 ) {
291 printf "No nm data for $fullname\n";
292 }
293 return;
294 }
295 $nmdata{$fullname} = \@nmdata;
296 }
298 sub drop_def
299 {
300 my ($object, $name) = @_;
301 my $nmdata = $nmdata{$object};
302 my ($i, $j);
303 for ($i = 0; $i <= $#{$nmdata}; ++$i) {
304 if ($name eq (split(' ', $nmdata->[$i], 2))[1]) {
305 splice(@{$nmdata{$object}}, $i, 1);
306 my $def = $def{$name};
307 for ($j = 0; $j < $#{$def{$name}}; ++$j) {
308 if ($def{$name}[$j] eq $object) {
309 splice(@{$def{$name}}, $j, 1);
310 }
311 }
312 last;
313 }
314 }
315 }
317 sub list_multiply_defined
318 {
319 my ($name, $module);
320 foreach $name (keys(%def)) {
321 if ($#{$def{$name}} > 0) {
322 # Special case for cond_syscall
323 if ($#{$def{$name}} == 1 && $name =~ /^sys_/ &&
324 ($def{$name}[0] eq "kernel/sys.o" ||
325 $def{$name}[1] eq "kernel/sys.o")) {
326 &drop_def("kernel/sys.o", $name);
327 next;
328 }
329 # Special case for i386 entry code
330 if ($#{$def{$name}} == 1 && $name =~ /^__kernel_/ &&
331 $def{$name}[0] eq "arch/i386/kernel/vsyscall-int80.o" &&
332 $def{$name}[1] eq "arch/i386/kernel/vsyscall-sysenter.o") {
333 &drop_def("arch/i386/kernel/vsyscall-sysenter.o", $name);
334 next;
335 }
336 printf "$name is multiply defined in :-\n";
337 foreach $module (@{$def{$name}}) {
338 printf "\t$module\n";
339 }
340 }
341 }
342 }
344 sub resolve_external_references
345 {
346 my ($object, $type, $name, $i, $j, $kstrtab, $ksymtab, $export);
347 printf "\n";
348 foreach $object (keys(%nmdata)) {
349 my $nmdata = $nmdata{$object};
350 for ($i = 0; $i <= $#{$nmdata}; ++$i) {
351 ($type, $name) = split(' ', $nmdata->[$i], 2);
352 if ($type eq "U" || $type eq "w") {
353 if (exists($def{$name}) || exists($ksymtab{$name})) {
354 # add the owning object to the nmdata
355 $nmdata->[$i] = "$type $name $object";
356 # only count as a reference if it is not EXPORT_...
357 $kstrtab = "R __kstrtab_$name";
358 $ksymtab = "R __ksymtab_$name";
359 $export = 0;
360 for ($j = 0; $j <= $#{$nmdata}; ++$j) {
361 if ($nmdata->[$j] eq $kstrtab ||
362 $nmdata->[$j] eq $ksymtab) {
363 $export = 1;
364 last;
365 }
366 }
367 if ($export) {
368 $export{$name} = "";
369 }
370 else {
371 $ref{$name} = ""
372 }
373 }
374 elsif ( $name ne "mod_use_count_"
375 && $name ne "__initramfs_end"
376 && $name ne "__initramfs_start"
377 && $name ne "_einittext"
378 && $name ne "_sinittext"
379 && $name ne "kallsyms_names"
380 && $name ne "kallsyms_num_syms"
381 && $name ne "kallsyms_addresses"
382 && $name ne "__this_module"
383 && $name ne "_etext"
384 && $name ne "_edata"
385 && $name ne "_end"
386 && $name ne "__bss_start"
387 && $name ne "_text"
388 && $name ne "_stext"
389 && $name ne "__gp"
390 && $name ne "ia64_unw_start"
391 && $name ne "ia64_unw_end"
392 && $name ne "__init_begin"
393 && $name ne "__init_end"
394 && $name ne "__bss_stop"
395 && $name ne "__nosave_begin"
396 && $name ne "__nosave_end"
397 && $name ne "pg0"
398 && $name ne "__module_text_address"
399 && $name !~ /^__sched_text_/
400 && $name !~ /^__start_/
401 && $name !~ /^__end_/
402 && $name !~ /^__stop_/
403 && $name !~ /^__scheduling_functions_.*_here/
404 && $name !~ /^__.*initcall_/
405 && $name !~ /^__.*per_cpu_start/
406 && $name !~ /^__.*per_cpu_end/
407 && $name !~ /^__alt_instructions/
408 && $name !~ /^__setup_/
409 && $name !~ /^jiffies/
410 && $name !~ /^__mod_timer/
411 && $name !~ /^__mod_page_state/
412 && $name !~ /^init_module/
413 && $name !~ /^cleanup_module/
414 ) {
415 printf "Cannot resolve ";
416 printf "weak " if ($type eq "w");
417 printf "reference to $name from $object\n";
418 }
419 }
420 }
421 }
422 }
424 sub list_extra_externals
425 {
426 my %noref = ();
427 my ($name, @module, $module, $export);
428 foreach $name (keys(%def)) {
429 if (! exists($ref{$name})) {
430 @module = @{$def{$name}};
431 foreach $module (@module) {
432 if (! exists($noref{$module})) {
433 $noref{$module} = [];
434 }
435 push(@{$noref{$module}}, $name);
436 }
437 }
438 }
439 if (%noref) {
440 printf "\nExternally defined symbols with no external references\n";
441 foreach $module (sort(keys(%noref))) {
442 printf " $module\n";
443 foreach (sort(@{$noref{$module}})) {
444 if (exists($export{$_})) {
445 $export = " (export only)";
446 }
447 else {
448 $export = "";
449 }
450 printf " $_$export\n";
451 }
452 }
453 }
454 }