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Diffstat (limited to 'docs/reference')
| -rw-r--r-- | docs/reference/buildsystem/buildrootmakefile.rst | 353 | ||||
| -rw-r--r-- | docs/reference/buildsystem/index.rst | 11 | ||||
| -rw-r--r-- | docs/reference/buildsystem/mainmakefile.md | 3 | ||||
| -rw-r--r-- | docs/reference/index.rst | 4 | ||||
| -rw-r--r-- | docs/reference/multiarch/index.rst | 11 | ||||
| -rw-r--r-- | docs/reference/multiarch/nodefns.rst | 160 |
6 files changed, 1 insertions, 541 deletions
diff --git a/docs/reference/buildsystem/buildrootmakefile.rst b/docs/reference/buildsystem/buildrootmakefile.rst deleted file mode 100644 index ef736220b25..00000000000 --- a/docs/reference/buildsystem/buildrootmakefile.rst +++ /dev/null @@ -1,353 +0,0 @@ -Introduction to build-root/Makefile -=================================== - -The vpp build system consists of a top-level Makefile, a data-driven -build-root/Makefile, and a set of makefile fragments. The various parts -come together as the result of a set of well-thought-out conventions. - -This section describes build-root/Makefile in some detail. - -Repository Groups and Source Paths ----------------------------------- - -Current vpp workspaces comprise a single repository group. The file -.../build-root/build-config.mk defines a key variable called -SOURCE\_PATH. The SOURCE\_PATH variable names the set of repository -groups. At the moment, there is only one repository group. - -Single pass build system, dependencies and components ------------------------------------------------------ - -The vpp build system caters to components built with GNU autoconf / -automake. Adding such components is a simple process. Dealing with -components which use BSD-style raw Makefiles is a more difficult. -Dealing with toolchain components such as gcc, glibc, and binutils can -be considerably more complicated. - -The vpp build system is a **single-pass** build system. A partial order -must exist for any set of components: the set of (a before b) tuples -must resolve to an ordered list. If you create a circular dependency of -the form; (a,b) (b,c) (c,a), gmake will try to build the target list, -but there’s a 0.0% chance that the results will be pleasant. Cut-n-paste -mistakes in .../build-data/packages/.mk can produce confusing failures. - -In a single-pass build system, it’s best to separate libraries and -applications which instantiate them. For example, if vpp depends on -libfoo.a, and myapp depends on both vpp and libfoo.a, it's best to place -libfoo.a and myapp in separate components. The build system will build -libfoo.a, vpp, and then (as a separate component) myapp. If you try to -build libfoo.a and myapp from the same component, it won’t work. - -If you absolutely, positively insist on having myapp and libfoo.a in the -same source tree, you can create a pseudo-component in a separate .mk -file in the .../build-data/packages/ directory. Define the code -phoneycomponent\_source = realcomponent, and provide manual -configure/build/install targets. - -Separate components for myapp, libfoo.a, and vpp is the best and easiest -solution. However, the “mumble\_source = realsource” degree of freedom -exists to solve intractable circular dependencies, such as: to build -gcc-bootstrap, followed by glibc, followed by “real” gcc/g++ [which -depends on glibc too]. - -.../build-root --------------- - -The .../build-root directory contains the repository group specification -build-config.mk, the main Makefile, and the system-wide set of -autoconf/automake variable overrides in config.site. We'll describe -these files in some detail. To be clear about expectations: the main -Makefile and config.site file are subtle and complex. It's unlikely that -you'll need or want to modify them. Poorly planned changes in either -place typically cause bugs that are difficult to solve. - -.../build-root/build-config.mk ------------------------------- - -As described above, the build-config.mk file is straightforward: it sets -the make variable SOURCE\_PATH to a list of repository group absolute -paths. - -The SOURCE\_PATH variable If you choose to move a workspace, make sure -to modify the paths defined by the SOURCE\_PATH variable. Those paths -need to match changes you make in the workspace paths. For example, if -you place the vpp directory in the workspace of a user named jsmith, you -might change the SOURCE\_PATH to: - -SOURCE\_PATH = /home/jsmithuser/workspace/vpp - -The "out of the box" setting should work 99.5% of the time: - -:: - - SOURCE_PATH = $(CURDIR)/.. - -.../vpp/build-root/Makefile ---------------------------- - -The main Makefile is complex in a number of dimensions. If you think you -need to modify it, it's a good idea to do some research, or ask for -advice before you change it. - -The main Makefile was organized and designed to provide the following -characteristics: excellent performance, accurate dependency processing, -cache enablement, timestamp optimizations, git integration, -extensibility, builds with cross-compilation tool chains, and builds -with embedded Linux distributions. - -If you really need to do so, you can build double-cross tools with it, -with a minimum amount of fuss. For example, you could: compile gdb on -x86\_64, to run on PowerPC, to debug the Xtensa instruction set. - -The PLATFORM variable ---------------------- - -The PLATFORM make/environment variable controls a number of important -characteristics, primarily: - -- CPU architecture -- The list of images to build. - -With respect to .../build-root/Makefile, the list of images to build is -specified by the target. For example: - -:: - - make PLATFORM=vpp TAG=vpp_debug install-deb - -builds vpp debug Debian packages. - -The main Makefile interprets $PLATFORM by attempting to "-include" the -file /build-data/platforms.mk: - -:: - - $(foreach d,$(FULL_SOURCE_PATH), \ - $(eval -include $(d)/platforms.mk)) - -By convention, we don't define **platforms** in the -...//build-data/platforms.mk file. - -In the vpp case, we search for platform definition makefile fragments in -.../vpp/build-data/platforms.mk, as follows: - -:: - - $(foreach d,$(SOURCE_PATH_BUILD_DATA_DIRS), \ - $(eval -include $(d)/platforms/*.mk)) - -With vpp, which uses the "vpp" platform as discussed above, we end up -"-include"-ing .../vpp/build-data/platforms/vpp.mk. - -The platform-specific .mk fragment ----------------------------------- - -Here are the contents of .../build-data/platforms/vpp.mk: - -:: - - MACHINE=$(shell uname -m) - - vpp_arch = native - ifeq ($(TARGET_PLATFORM),thunderx) - vpp_dpdk_target = arm64-thunderx-linuxapp-gcc - endif - vpp_native_tools = vppapigen - - vpp_uses_dpdk = yes - - # Uncoment to enable building unit tests - # vpp_enable_tests = yes - - vpp_root_packages = vpp vom japi - - # DPDK configuration parameters - # vpp_uses_dpdk_mlx4_pmd = yes - # vpp_uses_dpdk_mlx5_pmd = yes - # vpp_uses_external_dpdk = yes - # vpp_dpdk_inc_dir = /usr/include/dpdk - # vpp_dpdk_lib_dir = /usr/lib - # vpp_dpdk_shared_lib = yes - - # Use '--without-libnuma' for non-numa aware architecture - # Use '--enable-dlmalloc' to use dlmalloc instead of mheap - vpp_configure_args_vpp = --enable-dlmalloc - sample-plugin_configure_args_vpp = --enable-dlmalloc - - # load balancer plugin is not portable on 32 bit platform - ifeq ($(MACHINE),i686) - vpp_configure_args_vpp += --disable-lb-plugin - endif - - vpp_debug_TAG_CFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 \ - -fstack-protector-all -fPIC -Werror - vpp_debug_TAG_CXXFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 \ - -fstack-protector-all -fPIC -Werror - vpp_debug_TAG_LDFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 \ - -fstack-protector-all -fPIC -Werror - - vpp_TAG_CFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror - vpp_TAG_CXXFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror - vpp_TAG_LDFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror -pie -Wl,-z,now - - vpp_clang_TAG_CFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror - vpp_clang_TAG_LDFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror - - vpp_gcov_TAG_CFLAGS = -g -O0 -DCLIB_DEBUG -fPIC -Werror -fprofile-arcs -ftest-coverage - vpp_gcov_TAG_LDFLAGS = -g -O0 -DCLIB_DEBUG -fPIC -Werror -coverage - - vpp_coverity_TAG_CFLAGS = -g -O2 -fPIC -Werror -D__COVERITY__ - vpp_coverity_TAG_LDFLAGS = -g -O2 -fPIC -Werror -D__COVERITY__ - -Note the following variable settings: - -- The variable \_arch sets the CPU architecture used to build the - per-platform cross-compilation toolchain. With the exception of the - "native" architecture - used in our example - the vpp build system - produces cross-compiled binaries. - -- The variable \_native\_tools lists the required set of self-compiled - build tools. - -- The variable \_root\_packages lists the set of images to build when - specifying the target: make PLATFORM= TAG= [install-deb \| - install-rpm]. - -The TAG variable ----------------- - -The TAG variable indirectly sets CFLAGS and LDFLAGS, as well as the -build and install directory names in the .../vpp/build-root directory. -See definitions above. - -Important targets build-root/Makefile -------------------------------------- - -The main Makefile and the various makefile fragments implement the -following user-visible targets: - -+------------------+----------------------+--------------------------------------------------------------------------------------+ -| Target | ENV Variable Settings| Notes | -| | | | -+==================+======================+======================================================================================+ -| foo | bar | mumble | -+------------------+----------------------+--------------------------------------------------------------------------------------+ -| bootstrap-tools | none | Builds the set of native tools needed by the vpp build system to | -| | | build images. Example: vppapigen. In a full cross compilation case might include | -| | | include "make", "git", "find", and "tar | -+------------------+----------------------+--------------------------------------------------------------------------------------+ -| install-tools | PLATFORM | Builds the tool chain for the indicated <platform>. Not used in vpp builds | -+------------------+----------------------+--------------------------------------------------------------------------------------+ -| distclean | none | Roto-rooters everything in sight: toolchains, images, and so forth. | -+------------------+----------------------+--------------------------------------------------------------------------------------+ -| install-deb | PLATFORM and TAG | Build Debian packages comprising components listed in <platform>_root_packages, | -| | | using compile / link options defined by TAG. | -+------------------+----------------------+--------------------------------------------------------------------------------------+ -| install-rpm | PLATFORM and TAG | Build RPMs comprising components listed in <platform>_root_packages, | -| | | using compile / link options defined by TAG. | -+------------------+----------------------+--------------------------------------------------------------------------------------+ - -Additional build-root/Makefile environment variable settings ------------------------------------------------------------- - -These variable settings may be of use: - -+----------------------+------------------------------------------------------------------------------------------------------------+ -| ENV Variable | Notes | -+======================+======================+=====================================================================================+ -| BUILD_DEBUG=vx | Directs Makefile et al. to make a good-faith effort to show what's going on in excruciating detail. | -| | Use it as follows: "make ... BUILD_DEBUG=vx". Fairly effective in Makefile debug situations. | -+----------------------+------------------------------------------------------------------------------------------------------------+ -| V=1 | print detailed cc / ld command lines. Useful for discovering if -DFOO=11 is in the command line or not | -+----------------------+------------------------------------------------------------------------------------------------------------+ -| CC=mygcc | Override the configured C-compiler | -+----------------------+------------------------------------------------------------------------------------------------------------+ - -.../build-root/config.site --------------------------- - -The contents of .../build-root/config.site override individual autoconf / -automake default variable settings. Here are a few sample settings related to -building a full toolchain: - -:: - - # glibc needs these setting for cross compiling - libc_cv_forced_unwind=yes - libc_cv_c_cleanup=yes - libc_cv_ssp=no - -Determining the set of variables which need to be overridden, and the -override values is a matter of trial and error. It should be -unnecessary to modify this file for use with fd.io vpp. - -.../build-data/platforms.mk ---------------------------- - -Each repo group includes the platforms.mk file, which is included by -the main Makefile. The vpp/build-data/platforms.mk file is not terribly -complex. As of this writing, .../build-data/platforms.mk file accomplishes two -tasks. - -First, it includes vpp/build-data/platforms/\*.mk: - -:: - - # Pick up per-platform makefile fragments - $(foreach d,$(SOURCE_PATH_BUILD_DATA_DIRS), \ - $(eval -include $(d)/platforms/*.mk)) - -This collects the set of platform definition makefile fragments, as discussed above. - -Second, platforms.mk implements the user-visible "install-deb" target. - -.../build-data/packages/\*.mk ------------------------------ - -Each component needs a makefile fragment in order for the build system -to recognize it. The per-component makefile fragments vary -considerably in complexity. For a component built with GNU autoconf / -automake which does not depend on other components, the make fragment -can be empty. See .../build-data/packages/vpp.mk for an uncomplicated -but fully realistic example. - -Here are some of the important variable settings in per-component makefile fragments: - -+----------------------+------------------------------------------------------------------------------------------------------------+ -| Variable | Notes | -+======================+======================+=====================================================================================+ -| xxx_configure_depend | Lists the set of component build dependencies for the xxx component. In plain English: don't try to | -| | configure this component until you've successfully built the indicated targets. Almost always, | -| | xxx_configure_depend will list a set of "yyy-install" targets. Note the pattern: | -| | "variable names contain underscores, make target names contain hyphens" | -+----------------------+------------------------------------------------------------------------------------------------------------+ -| xxx_configure_args | (optional) Lists any additional arguments to pass to the xxx component "configure" script. | -| | The main Makefile %-configure rule adds the required settings for --libdir, --prefix, and | -| | --host (when cross-compiling) | -+----------------------+------------------------------------------------------------------------------------------------------------+ -| xxx_CPPFLAGS | Adds -I stanzas to CPPFLAGS for components upon which xxx depends. | -| | Almost invariably "xxx_CPPFLAGS = $(call installed_includes_fn, dep1 dep2 dep3)", where dep1, dep2, and | -| | dep3 are listed in xxx_configure_depend. It is bad practice to set "-g -O3" here. Those settings | -| | belong in a TAG. | -+----------------------+------------------------------------------------------------------------------------------------------------+ -| xxx_LDFLAGS | Adds -Wl,-rpath -Wl,depN stanzas to LDFLAGS for components upon which xxx depends. | -| | Almost invariably "xxx_LDFLAGS = $(call installed_lib_fn, dep1 dep2 dep3)", where dep1, dep2, and | -| | dep3 are listed in xxx_configure_depend. It is bad manners to set "-liberty-or-death" here. | -| | Those settings belong in Makefile.am. | -+----------------------+------------------------------------------------------------------------------------------------------------+ - -When dealing with "irritating" components built with raw Makefiles -which only work when building in the source tree, we use a specific -strategy in the xxx.mk file. - -The strategy is simple for those components: We copy the source tree -into .../vpp/build-root/build-xxx. This works, but completely defeats -dependency processing. This strategy is acceptable only for 3rd party -software which won't need extensive (or preferably any) modifications. - -Take a look at .../vpp/build-data/packages/dpdk.mk. When invoked, the -dpdk_configure variable copies source code into $(PACKAGE_BUILD_DIR), -and performs the BSD equivalent of "autoreconf -i -f" to configure the -build area. The rest of the file is similar: a bunch of hand-rolled -glue code which manages to make the dpdk act like a good vpp build -citizen even though it is not. diff --git a/docs/reference/buildsystem/index.rst b/docs/reference/buildsystem/index.rst deleted file mode 100644 index f7c512e255a..00000000000 --- a/docs/reference/buildsystem/index.rst +++ /dev/null @@ -1,11 +0,0 @@ -.. _buildsystem: - -Build System -============ - -This reference guide describes the vpp build system in detail - -.. toctree:: - - mainmakefile - buildrootmakefile diff --git a/docs/reference/buildsystem/mainmakefile.md b/docs/reference/buildsystem/mainmakefile.md deleted file mode 100644 index ddf0661942f..00000000000 --- a/docs/reference/buildsystem/mainmakefile.md +++ /dev/null @@ -1,3 +0,0 @@ -Introduction to the top-level Makefile -====================================== - diff --git a/docs/reference/index.rst b/docs/reference/index.rst index 48b5170d69c..23ddecdc280 100644 --- a/docs/reference/index.rst +++ b/docs/reference/index.rst @@ -7,9 +7,7 @@ Reference .. toctree:: :maxdepth: 2 + vppvagrant/index.rst readthedocs/index.rst github/index.rst - vppvagrant/index.rst - buildsystem/index.rst - multiarch/index.rst cmdreference/index.rst diff --git a/docs/reference/multiarch/index.rst b/docs/reference/multiarch/index.rst deleted file mode 100644 index 48065b8a8e2..00000000000 --- a/docs/reference/multiarch/index.rst +++ /dev/null @@ -1,11 +0,0 @@ -.. _multiarch: - -Multi-architecture support -========================== - -This reference guide describes how to use the vpp muli-architecture support scheme - -.. toctree:: - :maxdepth: 1 - - nodefns diff --git a/docs/reference/multiarch/nodefns.rst b/docs/reference/multiarch/nodefns.rst deleted file mode 100644 index ad68385d6c5..00000000000 --- a/docs/reference/multiarch/nodefns.rst +++ /dev/null @@ -1,160 +0,0 @@ -Multi-Architecture Graph Node Cookbook -====================================== - -In the context of graph node dispatch functions, it's easy enough to -use the vpp multi-architecture support setup. The point of the scheme -is simple: for performance-critical nodes, generate multiple CPU -hardware-dependent versions of the node dispatch functions, and pick -the best one at runtime. - -The vpp scheme is simple enough to use, but details matter. - -100,000 foot view ------------------ - -We compile entire graph node dispatch function implementation files -multiple times. These compilations give rise to multiple versions of -the graph node dispatch functions. Per-node constructor-functions -interrogate CPU hardware, select the node dispatch function variant to -use, and set the vlib_node_registration_t ".function" member to the -address of the selected variant. - -Details -------- - -Declare the node dispatch function as shown, using the VLIB\_NODE\_FN macro. The -name of the node function **MUST** match the name of the graph node. - -:: - - VLIB_NODE_FN (ip4_sdp_node) (vlib_main_t * vm, vlib_node_runtime_t * node, - vlib_frame_t * frame) - { - if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE)) - return ip46_sdp_inline (vm, node, frame, 1 /* is_ip4 */ , - 1 /* is_trace */ ); - else - return ip46_sdp_inline (vm, node, frame, 1 /* is_ip4 */ , - 0 /* is_trace */ ); - } - -We need to generate *precisely one copy* of the -vlib_node_registration_t, error strings, and packet trace decode function. - -Simply bracket these items with "#ifndef CLIB_MARCH_VARIANT...#endif": - -:: - - #ifndef CLIB_MARCH_VARIANT - static u8 * - format_sdp_trace (u8 * s, va_list * args) - { - <snip> - } - #endif - - ... - - #ifndef CLIB_MARCH_VARIANT - static char *sdp_error_strings[] = { - #define _(sym,string) string, - foreach_sdp_error - #undef _ - }; - #endif - - ... - - #ifndef CLIB_MARCH_VARIANT - VLIB_REGISTER_NODE (ip4_sdp_node) = - { - // DO NOT set the .function structure member. - // The multiarch selection __attribute__((constructor)) function - // takes care of it at runtime - .name = "ip4-sdp", - .vector_size = sizeof (u32), - .format_trace = format_sdp_trace, - .type = VLIB_NODE_TYPE_INTERNAL, - - .n_errors = ARRAY_LEN(sdp_error_strings), - .error_strings = sdp_error_strings, - - .n_next_nodes = SDP_N_NEXT, - - /* edit / add dispositions here */ - .next_nodes = - { - [SDP_NEXT_DROP] = "ip4-drop", - }, - }; - #endif - -To belabor the point: *do not* set the ".function" member! That's the job of the multi-arch -selection \_\_attribute\_\_((constructor)) function - -Always inline node dispatch functions -------------------------------------- - -It's typical for a graph dispatch function to contain one or more -calls to an inline function. See above. If your node dispatch function -is structured that way, make *ABSOLUTELY CERTAIN* to use the -"always_inline" macro: - -:: - - always_inline uword - ip46_sdp_inline (vlib_main_t * vm, vlib_node_runtime_t * node, - vlib_frame_t * frame, - int is_ip4, int is_trace) - { ... } - -Otherwise, the compiler is highly likely NOT to build multiple -versions of the guts of your dispatch function. - -It's fairly easy to spot this mistake in "perf top." If you see, for -example, a bunch of functions with names of the form -"xxx_node_fn_avx2" in the profile, *BUT* your brand-new node function -shows up with a name of the form "xxx_inline.isra.1", it's quite likely -that the inline was declared "static inline" instead of "always_inline". - -Add the required Makefile.am content ------------------------------------- - -If the component in question already sets a "multiversioning_sources" -variable, simply add the indicated .c file to the list. If not, add -the required boilerplate: - -:: - - if CPU_X86_64 - sdp_multiversioning_sources = \ - sdp/node.c \ - sdp/sdp_slookup.c - - if CC_SUPPORTS_AVX2 - ############################################################### - # AVX2 - ############################################################### - libsdp_plugin_avx2_la_SOURCES = $(sdp_multiversioning_sources) - libsdp_plugin_avx2_la_CFLAGS = \ - $(AM_CFLAGS) @CPU_AVX2_FLAGS@ \ - -DCLIB_MARCH_VARIANT=avx2 - noinst_LTLIBRARIES += libsdp_plugin_avx2.la - sdp_plugin_la_LIBADD += libsdp_plugin_avx2.la - endif - - if CC_SUPPORTS_AVX512 - ############################################################### - # AVX512 - ############################################################### - libsdp_plugin_avx512_la_SOURCES = $(sdp_multiversioning_sources) - libsdp_plugin_avx512_la_CFLAGS = \ - $(AM_CFLAGS) @CPU_AVX512_FLAGS@ \ - -DCLIB_MARCH_VARIANT=avx512 - noinst_LTLIBRARIES += libsdp_plugin_avx512.la - sdp_plugin_la_LIBADD += libsdp_plugin_avx512.la - endif - endif - -A certain amount of cut-paste-modify is currently required. Hopefully -we'll manage to improve the scheme in the future. |