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authorScott Rifenbark <srifenbark@gmail.com>2018-05-16 15:07:08 -0700
committerRichard Purdie <richard.purdie@linuxfoundation.org>2018-05-24 17:16:35 +0100
commit9a37a3d568a04319cece45edfa04e787e06c4399 (patch)
tree8b5ba82adfcaf99d242f0e7ed6b04b56f41cdfc5 /documentation/dev-manual
parentbd4438f4a4c945458fa9e373d0fe51886af8f49c (diff)
downloadpoky-9a37a3d568a04319cece45edfa04e787e06c4399.tar.gz
dev-manual: Moved "Speeding Up the Build" and renamed it.
Renamed to "Speeding Up a Build" and moved out of the setting up chapter to the common tasks chapter. Fixed a couple links in the ref-manual. (From yocto-docs rev: c53fddd353230c8ef1abc21c7a2d2b1f492f034a) Signed-off-by: Scott Rifenbark <srifenbark@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/dev-manual')
-rw-r--r--documentation/dev-manual/dev-manual-common-tasks.xml161
-rw-r--r--documentation/dev-manual/dev-manual-start.xml160
2 files changed, 158 insertions, 163 deletions
diff --git a/documentation/dev-manual/dev-manual-common-tasks.xml b/documentation/dev-manual/dev-manual-common-tasks.xml
index d4b99bc69f..9e8dd5fa92 100644
--- a/documentation/dev-manual/dev-manual-common-tasks.xml
+++ b/documentation/dev-manual/dev-manual-common-tasks.xml
@@ -6224,11 +6224,166 @@
6224 6224
6225 6225
6226 6226
6227 <section id='speeding-up-a-build'>
6228 <title>Speeding Up a Build</title>
6227 6229
6230 <para>
6231 Build time can be an issue.
6232 By default, the build system uses simple controls to try and maximize
6233 build efficiency.
6234 In general, the default settings for all the following variables
6235 result in the most efficient build times when dealing with single
6236 socket systems (i.e. a single CPU).
6237 If you have multiple CPUs, you might try increasing the default
6238 values to gain more speed.
6239 See the descriptions in the glossary for each variable for more
6240 information:
6241 <itemizedlist>
6242 <listitem><para>
6243 <ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename>:</ulink>
6244 The maximum number of threads BitBake simultaneously executes.
6245 </para></listitem>
6246 <listitem><para>
6247 <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_NUMBER_PARSE_THREADS'><filename>BB_NUMBER_PARSE_THREADS</filename>:</ulink>
6248 The number of threads BitBake uses during parsing.
6249 </para></listitem>
6250 <listitem><para>
6251 <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename>:</ulink>
6252 Extra options passed to the <filename>make</filename> command
6253 during the
6254 <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-compile'><filename>do_compile</filename></ulink>
6255 task in order to specify parallel compilation on the
6256 local build host.
6257 </para></listitem>
6258 <listitem><para>
6259 <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKEINST'><filename>PARALLEL_MAKEINST</filename>:</ulink>
6260 Extra options passed to the <filename>make</filename> command
6261 during the
6262 <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-install'><filename>do_install</filename></ulink>
6263 task in order to specify parallel installation on the
6264 local build host.
6265 </para></listitem>
6266 </itemizedlist>
6267 As mentioned, these variables all scale to the number of processor
6268 cores available on the build system.
6269 For single socket systems, this auto-scaling ensures that the build
6270 system fundamentally takes advantage of potential parallel operations
6271 during the build based on the build machine's capabilities.
6272 </para>
6228 6273
6229 6274 <para>
6230 6275 Following are additional factors that can affect build speed:
6231 6276 <itemizedlist>
6277 <listitem><para>
6278 File system type:
6279 The file system type that the build is being performed on can
6280 also influence performance.
6281 Using <filename>ext4</filename> is recommended as compared
6282 to <filename>ext2</filename> and <filename>ext3</filename>
6283 due to <filename>ext4</filename> improved features
6284 such as extents.
6285 </para></listitem>
6286 <listitem><para>
6287 Disabling the updating of access time using
6288 <filename>noatime</filename>:
6289 The <filename>noatime</filename> mount option prevents the
6290 build system from updating file and directory access times.
6291 </para></listitem>
6292 <listitem><para>
6293 Setting a longer commit:
6294 Using the "commit=" mount option increases the interval
6295 in seconds between disk cache writes.
6296 Changing this interval from the five second default to
6297 something longer increases the risk of data loss but decreases
6298 the need to write to the disk, thus increasing the build
6299 performance.
6300 </para></listitem>
6301 <listitem><para>
6302 Choosing the packaging backend:
6303 Of the available packaging backends, IPK is the fastest.
6304 Additionally, selecting a singular packaging backend also
6305 helps.
6306 </para></listitem>
6307 <listitem><para>
6308 Using <filename>tmpfs</filename> for
6309 <ulink url='&YOCTO_DOCS_REF_URL;#var-TMPDIR'><filename>TMPDIR</filename></ulink>
6310 as a temporary file system:
6311 While this can help speed up the build, the benefits are
6312 limited due to the compiler using
6313 <filename>-pipe</filename>.
6314 The build system goes to some lengths to avoid
6315 <filename>sync()</filename> calls into the
6316 file system on the principle that if there was a significant
6317 failure, the
6318 <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>
6319 contents could easily be rebuilt.
6320 </para></listitem>
6321 <listitem><para>
6322 Inheriting the
6323 <ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-rm-work'><filename>rm_work</filename></ulink>
6324 class:
6325 Inheriting this class has shown to speed up builds due to
6326 significantly lower amounts of data stored in the data
6327 cache as well as on disk.
6328 Inheriting this class also makes cleanup of
6329 <ulink url='&YOCTO_DOCS_REF_URL;#var-TMPDIR'><filename>TMPDIR</filename></ulink>
6330 faster, at the expense of being easily able to dive into the
6331 source code.
6332 File system maintainers have recommended that the fastest way
6333 to clean up large numbers of files is to reformat partitions
6334 rather than delete files due to the linear nature of
6335 partitions.
6336 This, of course, assumes you structure the disk partitions and
6337 file systems in a way that this is practical.
6338 </para></listitem>
6339 </itemizedlist>
6340 Aside from the previous list, you should keep some trade offs in
6341 mind that can help you speed up the build:
6342 <itemizedlist>
6343 <listitem><para>
6344 Remove items from
6345 <ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></ulink>
6346 that you might not need.
6347 </para></listitem>
6348 <listitem><para>
6349 Exclude debug symbols and other debug information:
6350 If you do not need these symbols and other debug information,
6351 disabling the <filename>*-dbg</filename> package generation
6352 can speed up the build.
6353 You can disable this generation by setting the
6354 <ulink url='&YOCTO_DOCS_REF_URL;#var-INHIBIT_PACKAGE_DEBUG_SPLIT'><filename>INHIBIT_PACKAGE_DEBUG_SPLIT</filename></ulink>
6355 variable to "1".
6356 </para></listitem>
6357 <listitem><para>
6358 Disable static library generation for recipes derived from
6359 <filename>autoconf</filename> or <filename>libtool</filename>:
6360 Following is an example showing how to disable static
6361 libraries and still provide an override to handle exceptions:
6362 <literallayout class='monospaced'>
6363 STATICLIBCONF = "--disable-static"
6364 STATICLIBCONF_sqlite3-native = ""
6365 EXTRA_OECONF += "${STATICLIBCONF}"
6366 </literallayout>
6367 <note><title>Notes</title>
6368 <itemizedlist>
6369 <listitem><para>
6370 Some recipes need static libraries in order to work
6371 correctly (e.g. <filename>pseudo-native</filename>
6372 needs <filename>sqlite3-native</filename>).
6373 Overrides, as in the previous example, account for
6374 these kinds of exceptions.
6375 </para></listitem>
6376 <listitem><para>
6377 Some packages have packaging code that assumes the
6378 presence of the static libraries.
6379 If so, you might need to exclude them as well.
6380 </para></listitem>
6381 </itemizedlist>
6382 </note>
6383 </para></listitem>
6384 </itemizedlist>
6385 </para>
6386 </section>
6232 6387
6233 <section id="platdev-working-with-libraries"> 6388 <section id="platdev-working-with-libraries">
6234 <title>Working With Libraries</title> 6389 <title>Working With Libraries</title>
diff --git a/documentation/dev-manual/dev-manual-start.xml b/documentation/dev-manual/dev-manual-start.xml
index 201cbe7340..d8726b4857 100644
--- a/documentation/dev-manual/dev-manual-start.xml
+++ b/documentation/dev-manual/dev-manual-start.xml
@@ -1080,166 +1080,6 @@
1080 </section> 1080 </section>
1081</section> 1081</section>
1082 1082
1083<section id='speeding-up-the-build'>
1084 <title>Speeding Up the Build</title>
1085
1086 <para>
1087 Build time can be an issue.
1088 By default, the build system uses simple controls to try and maximize
1089 build efficiency.
1090 In general, the default settings for all the following variables
1091 result in the most efficient build times when dealing with single
1092 socket systems (i.e. a single CPU).
1093 If you have multiple CPUs, you might try increasing the default
1094 values to gain more speed.
1095 See the descriptions in the glossary for each variable for more
1096 information:
1097 <itemizedlist>
1098 <listitem><para>
1099 <ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'><filename>BB_NUMBER_THREADS</filename>:</ulink>
1100 The maximum number of threads BitBake simultaneously executes.
1101 </para></listitem>
1102 <listitem><para>
1103 <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_NUMBER_PARSE_THREADS'><filename>BB_NUMBER_PARSE_THREADS</filename>:</ulink>
1104 The number of threads BitBake uses during parsing.
1105 </para></listitem>
1106 <listitem><para>
1107 <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'><filename>PARALLEL_MAKE</filename>:</ulink>
1108 Extra options passed to the <filename>make</filename> command
1109 during the
1110 <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-compile'><filename>do_compile</filename></ulink>
1111 task in order to specify parallel compilation on the
1112 local build host.
1113 </para></listitem>
1114 <listitem><para>
1115 <ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKEINST'><filename>PARALLEL_MAKEINST</filename>:</ulink>
1116 Extra options passed to the <filename>make</filename> command
1117 during the
1118 <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-install'><filename>do_install</filename></ulink>
1119 task in order to specify parallel installation on the
1120 local build host.
1121 </para></listitem>
1122 </itemizedlist>
1123 As mentioned, these variables all scale to the number of processor
1124 cores available on the build system.
1125 For single socket systems, this auto-scaling ensures that the build
1126 system fundamentally takes advantage of potential parallel operations
1127 during the build based on the build machine's capabilities.
1128 </para>
1129
1130 <para>
1131 Following are additional factors that can affect build speed:
1132 <itemizedlist>
1133 <listitem><para>
1134 File system type:
1135 The file system type that the build is being performed on can
1136 also influence performance.
1137 Using <filename>ext4</filename> is recommended as compared
1138 to <filename>ext2</filename> and <filename>ext3</filename>
1139 due to <filename>ext4</filename> improved features
1140 such as extents.
1141 </para></listitem>
1142 <listitem><para>
1143 Disabling the updating of access time using
1144 <filename>noatime</filename>:
1145 The <filename>noatime</filename> mount option prevents the
1146 build system from updating file and directory access times.
1147 </para></listitem>
1148 <listitem><para>
1149 Setting a longer commit:
1150 Using the "commit=" mount option increases the interval
1151 in seconds between disk cache writes.
1152 Changing this interval from the five second default to
1153 something longer increases the risk of data loss but decreases
1154 the need to write to the disk, thus increasing the build
1155 performance.
1156 </para></listitem>
1157 <listitem><para>
1158 Choosing the packaging backend:
1159 Of the available packaging backends, IPK is the fastest.
1160 Additionally, selecting a singular packaging backend also
1161 helps.
1162 </para></listitem>
1163 <listitem><para>
1164 Using <filename>tmpfs</filename> for
1165 <ulink url='&YOCTO_DOCS_REF_URL;#var-TMPDIR'><filename>TMPDIR</filename></ulink>
1166 as a temporary file system:
1167 While this can help speed up the build, the benefits are
1168 limited due to the compiler using
1169 <filename>-pipe</filename>.
1170 The build system goes to some lengths to avoid
1171 <filename>sync()</filename> calls into the
1172 file system on the principle that if there was a significant
1173 failure, the
1174 <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>
1175 contents could easily be rebuilt.
1176 </para></listitem>
1177 <listitem><para>
1178 Inheriting the
1179 <ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-rm-work'><filename>rm_work</filename></ulink>
1180 class:
1181 Inheriting this class has shown to speed up builds due to
1182 significantly lower amounts of data stored in the data
1183 cache as well as on disk.
1184 Inheriting this class also makes cleanup of
1185 <ulink url='&YOCTO_DOCS_REF_URL;#var-TMPDIR'><filename>TMPDIR</filename></ulink>
1186 faster, at the expense of being easily able to dive into the
1187 source code.
1188 File system maintainers have recommended that the fastest way
1189 to clean up large numbers of files is to reformat partitions
1190 rather than delete files due to the linear nature of
1191 partitions.
1192 This, of course, assumes you structure the disk partitions and
1193 file systems in a way that this is practical.
1194 </para></listitem>
1195 </itemizedlist>
1196 Aside from the previous list, you should keep some trade offs in
1197 mind that can help you speed up the build:
1198 <itemizedlist>
1199 <listitem><para>
1200 Remove items from
1201 <ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></ulink>
1202 that you might not need.
1203 </para></listitem>
1204 <listitem><para>
1205 Exclude debug symbols and other debug information:
1206 If you do not need these symbols and other debug information,
1207 disabling the <filename>*-dbg</filename> package generation
1208 can speed up the build.
1209 You can disable this generation by setting the
1210 <ulink url='&YOCTO_DOCS_REF_URL;#var-INHIBIT_PACKAGE_DEBUG_SPLIT'><filename>INHIBIT_PACKAGE_DEBUG_SPLIT</filename></ulink>
1211 variable to "1".
1212 </para></listitem>
1213 <listitem><para>
1214 Disable static library generation for recipes derived from
1215 <filename>autoconf</filename> or <filename>libtool</filename>:
1216 Following is an example showing how to disable static
1217 libraries and still provide an override to handle exceptions:
1218 <literallayout class='monospaced'>
1219 STATICLIBCONF = "--disable-static"
1220 STATICLIBCONF_sqlite3-native = ""
1221 EXTRA_OECONF += "${STATICLIBCONF}"
1222 </literallayout>
1223 <note><title>Notes</title>
1224 <itemizedlist>
1225 <listitem><para>
1226 Some recipes need static libraries in order to work
1227 correctly (e.g. <filename>pseudo-native</filename>
1228 needs <filename>sqlite3-native</filename>).
1229 Overrides, as in the previous example, account for
1230 these kinds of exceptions.
1231 </para></listitem>
1232 <listitem><para>
1233 Some packages have packaging code that assumes the
1234 presence of the static libraries.
1235 If so, you might need to exclude them as well.
1236 </para></listitem>
1237 </itemizedlist>
1238 </note>
1239 </para></listitem>
1240 </itemizedlist>
1241 </para>
1242</section>
1243</chapter> 1083</chapter>
1244<!-- 1084<!--
1245vim: expandtab tw=80 ts=4 1085vim: expandtab tw=80 ts=4
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