![]() In bpftool's Makefile, libbpf has a FORCE dependency, to make sure we rebuild it in case its source files changed. Let's instead make the rebuild depend on the source files directly, through a call to the "$(wildcard ...)" function. This avoids descending into libbpf's directory if there is nothing to update. Do the same for the bootstrap libbpf version. This results in a slightly faster operation and less verbose output when running make a second time in bpftool's directory. Before: Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] make[1]: Entering directory '/root/dev/linux/tools/lib/bpf' make[1]: Entering directory '/root/dev/linux/tools/lib/bpf' make[1]: Nothing to be done for 'install_headers'. make[1]: Leaving directory '/root/dev/linux/tools/lib/bpf' make[1]: Leaving directory '/root/dev/linux/tools/lib/bpf' After: Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] Other ways to clean up the output could be to pass the "-s" option, or to redirect the output to >/dev/null, when calling make recursively to descend into libbpf's directory. However, this would suppress some useful output if something goes wrong during the build. A better alternative would be to pass "--no-print-directory" to the recursive make, but that would still leave us with some noise for "install_headers". Skipping the descent into libbpf's directory if no source file has changed works best, and seems the most logical option overall. Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20211009210341.6291-3-quentin@isovalent.com |
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Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.