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qemu-android / qemu-android / 49f676a00ab540fac1d2008be26434cf85607722
commit49f676a00ab540fac1d2008be26434cf85607722[log] [tgz]
authorPeter Lieven <pl@kamp.de>Tue Mar 26 10:58:34 2013 +0100
committerJuan Quintela <quintela@redhat.com>Tue Mar 26 13:32:32 2013 +0100
treecce8a4ec1cca6877846d177c9efc17fc26aee98d
parent56ded708ec38e4cb75a7c7357480ca34c0dc6875 [diff]
bitops: unroll while loop in find_next_bit()

this patch adopts the loop unrolling idea of bitmap_is_zero() to
speed up the skipping of large areas with zeros in find_next_bit().

this routine is extensively used to find dirty pages in
live migration.

testing only the find_next_bit performance on a zeroed bitfield
the loop onrolling decreased executing time by approx. 50% on x86_64.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
1 file changed
tree: cce8a4ec1cca6877846d177c9efc17fc26aee98d
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. default-configs/
  6. disas/
  7. docs/
  8. fpu/
  9. fsdev/
  10. gdb-xml/
  11. hw/
  12. include/
  13. ldscripts/
  14. libcacard/
  15. linux-headers/
  16. linux-user/
  17. net/
  18. pc-bios/
  19. po/
  20. qapi/
  21. qga/
  22. QMP/
  23. qobject/
  24. qom/
  25. roms/
  26. scripts/
  27. slirp/
  28. stubs/
  29. sysconfigs/
  30. target-alpha/
  31. target-arm/
  32. target-cris/
  33. target-i386/
  34. target-lm32/
  35. target-m68k/
  36. target-microblaze/
  37. target-mips/
  38. target-moxie/
  39. target-openrisc/
  40. target-ppc/
  41. target-s390x/
  42. target-sh4/
  43. target-sparc/
  44. target-unicore32/
  45. target-xtensa/
  46. tcg/
  47. tests/
  48. tpm/
  49. trace/
  50. ui/
  51. util/
  52. pixman
  53. .exrc
  54. .gitignore
  55. .gitmodules
  56. .mailmap
  57. aio-posix.c
  58. aio-win32.c
  59. arch_init.c
  60. async.c
  61. balloon.c
  62. block-migration.c
  63. block.c
  64. blockdev-nbd.c
  65. blockdev.c
  66. blockjob.c
  67. bt-host.c
  68. bt-vhci.c
  69. Changelog
  70. cmd.c
  71. cmd.h
  72. CODING_STYLE
  73. configure
  74. COPYING
  75. COPYING.LIB
  76. coroutine-gthread.c
  77. coroutine-sigaltstack.c
  78. coroutine-ucontext.c
  79. coroutine-win32.c
  80. cpu-exec.c
  81. cpus.c
  82. cputlb.c
  83. device-hotplug.c
  84. device_tree.c
  85. disas.c
  86. dma-helpers.c
  87. dump-stub.c
  88. dump.c
  89. exec.c
  90. gdbstub.c
  91. HACKING
  92. hmp-commands.hx
  93. hmp.c
  94. hmp.h
  95. iohandler.c
  96. ioport.c
  97. kvm-all.c
  98. kvm-stub.c
  99. LICENSE
  100. main-loop.c
  101. MAINTAINERS
  102. Makefile
  103. Makefile.objs
  104. Makefile.target
  105. memory.c
  106. memory_mapping-stub.c
  107. memory_mapping.c
  108. migration-exec.c
  109. migration-fd.c
  110. migration-tcp.c
  111. migration-unix.c
  112. migration.c
  113. monitor.c
  114. nbd.c
  115. os-posix.c
  116. os-win32.c
  117. page_cache.c
  118. qapi-schema-test.json
  119. qapi-schema.json
  120. qdev-monitor.c
  121. qdict-test-data.txt
  122. qemu-bridge-helper.c
  123. qemu-char.c
  124. qemu-coroutine-io.c
  125. qemu-coroutine-lock.c
  126. qemu-coroutine-sleep.c
  127. qemu-coroutine.c
  128. qemu-doc.texi
  129. qemu-img-cmds.hx
  130. qemu-img.c
  131. qemu-img.texi
  132. qemu-io.c
  133. qemu-log.c
  134. qemu-nbd.c
  135. qemu-nbd.texi
  136. qemu-options-wrapper.h
  137. qemu-options.h
  138. qemu-options.hx
  139. qemu-seccomp.c
  140. qemu-tech.texi
  141. qemu-timer.c
  142. qemu.sasl
  143. qmp-commands.hx
  144. qmp.c
  145. qtest.c
  146. readline.c
  147. README
  148. rules.mak
  149. savevm.c
  150. spice-qemu-char.c
  151. tcg-runtime.c
  152. tci.c
  153. thread-pool.c
  154. thunk.c
  155. trace-events
  156. translate-all.c
  157. translate-all.h
  158. user-exec.c
  159. VERSION
  160. version.rc
  161. vl.c
  162. xbzrle.c
  163. xen-all.c
  164. xen-mapcache.c
  165. xen-stub.c