mirror of https://github.com/torvalds/linux.git
523f3dbc18
Contrary to expectations, passing a single candidate tag to "git
describe" is slower than not passing any --match options.
$ time git describe --debug
...
traversed 10619 commits
...
v6.12-rc5-63-g0fc810ae3ae1
real 0m0.169s
$ time git describe --match=v6.12-rc5 --debug
...
traversed 1310024 commits
v6.12-rc5-63-g0fc810ae3ae1
real 0m1.281s
In fact, the --debug output shows that git traverses all or most of
history. For some repositories and/or git versions, those 1.3s are
actually 10-15 seconds.
This has been acknowledged as a performance bug in git [1], and a fix
is on its way [2]. However, no solution is yet in git.git, and even
when one lands, it will take quite a while before it finds its way to
a release and for $random_kernel_developer to pick that up.
So rewrite the logic to use plumbing commands. For each of the
candidate values of $tag, we ask: (1) is $tag even an annotated
tag? (2) Is it eligible to describe HEAD, i.e. an ancestor of
HEAD? (3) If so, how many commits are in $tag..HEAD?
I have tested that this produces the same output as the current script
for ~700 random commits between v6.9..v6.10. For those 700 commits,
and in my git repo, the 'make -s kernelrelease' command is on average
~4 times faster with this patch applied (geometric mean of ratios).
For the commit mentioned in Josh's original report [3], the
time-consuming part of setlocalversion goes from
$ time git describe --match=v6.12-rc5
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|---|---|---|
| .. | ||
| atomic | ||
| basic | ||
| clang-tools | ||
| coccinelle | ||
| dtc | ||
| dummy-tools | ||
| gcc-plugins | ||
| gdb | ||
| genksyms | ||
| include | ||
| ipe | ||
| kconfig | ||
| ksymoops | ||
| mod | ||
| package | ||
| selinux | ||
| tracing | ||
| .gitignore | ||
| Kbuild.include | ||
| Kconfig.include | ||
| Lindent | ||
| Makefile | ||
| Makefile.asm-headers | ||
| Makefile.autofdo | ||
| Makefile.btf | ||
| Makefile.build | ||
| Makefile.clang | ||
| Makefile.clean | ||
| Makefile.compiler | ||
| Makefile.debug | ||
| Makefile.defconf | ||
| Makefile.dtbinst | ||
| Makefile.dtbs | ||
| Makefile.extrawarn | ||
| Makefile.gcc-plugins | ||
| Makefile.headersinst | ||
| Makefile.host | ||
| Makefile.kasan | ||
| Makefile.kcov | ||
| Makefile.kcsan | ||
| Makefile.kmsan | ||
| Makefile.lib | ||
| Makefile.modfinal | ||
| Makefile.modinst | ||
| Makefile.modpost | ||
| Makefile.package | ||
| Makefile.propeller | ||
| Makefile.randstruct | ||
| Makefile.ubsan | ||
| Makefile.userprogs | ||
| Makefile.vdsoinst | ||
| Makefile.vmlinux | ||
| Makefile.vmlinux_o | ||
| as-version.sh | ||
| asn1_compiler.c | ||
| bloat-o-meter | ||
| bootgraph.pl | ||
| bpf_doc.py | ||
| build-version | ||
| cc-can-link.sh | ||
| cc-version.sh | ||
| check-git | ||
| check-sysctl-docs | ||
| check-uapi.sh | ||
| check-variable-fonts.sh | ||
| check_extable.sh | ||
| checkdeclares.pl | ||
| checkincludes.pl | ||
| checkkconfigsymbols.py | ||
| checkpatch.pl | ||
| checkstack.pl | ||
| checksyscalls.sh | ||
| checktransupdate.py | ||
| checkversion.pl | ||
| cleanfile | ||
| cleanpatch | ||
| coccicheck | ||
| config | ||
| const_structs.checkpatch | ||
| decode_stacktrace.sh | ||
| decodecode | ||
| depmod.sh | ||
| dev-needs.sh | ||
| diffconfig | ||
| documentation-file-ref-check | ||
| export_report.pl | ||
| extract-ikconfig | ||
| extract-module-sig.pl | ||
| extract-sys-certs.pl | ||
| extract-vmlinux | ||
| extract_xc3028.pl | ||
| faddr2line | ||
| file-size.sh | ||
| find-unused-docs.sh | ||
| gcc-x86_32-has-stack-protector.sh | ||
| gcc-x86_64-has-stack-protector.sh | ||
| gen-randstruct-seed.sh | ||
| generate_builtin_ranges.awk | ||
| generate_initcall_order.pl | ||
| generate_rust_analyzer.py | ||
| generate_rust_target.rs | ||
| get_abi.pl | ||
| get_dvb_firmware | ||
| get_feat.pl | ||
| get_maintainer.pl | ||
| gfp-translate | ||
| git.orderFile | ||
| head-object-list.txt | ||
| headerdep.pl | ||
| headers_install.sh | ||
| insert-sys-cert.c | ||
| install.sh | ||
| jobserver-exec | ||
| kallsyms.c | ||
| kernel-doc | ||
| ld-version.sh | ||
| leaking_addresses.pl | ||
| link-vmlinux.sh | ||
| macro_checker.py | ||
| make_fit.py | ||
| makelst | ||
| markup_oops.pl | ||
| min-tool-version.sh | ||
| misc-check | ||
| mkcompile_h | ||
| mksysmap | ||
| mkuboot.sh | ||
| module-common.c | ||
| module.lds.S | ||
| modules-check.sh | ||
| nsdeps | ||
| objdiff | ||
| objdump-func | ||
| orc_hash.sh | ||
| pahole-version.sh | ||
| parse-maintainers.pl | ||
| patch-kernel | ||
| profile2linkerlist.pl | ||
| prune-kernel | ||
| recordmcount.c | ||
| recordmcount.h | ||
| recordmcount.pl | ||
| relocs_check.sh | ||
| remove-stale-files | ||
| rust_is_available.sh | ||
| rust_is_available_bindgen_0_66.h | ||
| rust_is_available_bindgen_libclang.h | ||
| rust_is_available_test.py | ||
| rustc-llvm-version.sh | ||
| rustc-version.sh | ||
| rustdoc_test_builder.rs | ||
| rustdoc_test_gen.rs | ||
| setlocalversion | ||
| show_delta | ||
| sign-file.c | ||
| sorttable.c | ||
| sorttable.h | ||
| spdxcheck-test.sh | ||
| spdxcheck.py | ||
| spdxexclude | ||
| spelling.txt | ||
| sphinx-pre-install | ||
| split-man.pl | ||
| ssl-common.h | ||
| stackdelta | ||
| stackusage | ||
| subarch.include | ||
| syscall.tbl | ||
| syscallhdr.sh | ||
| syscallnr.sh | ||
| syscalltbl.sh | ||
| tags.sh | ||
| tools-support-relr.sh | ||
| unifdef.c | ||
| ver_linux | ||
| verify_builtin_ranges.awk | ||
| xen-hypercalls.sh | ||
| xz_wrap.sh | ||