Add a rather trivial "spatchcache", with this running e.g.:
make cocciclean
make contrib/coccinelle/free.cocci.patch \
SPATCH=contrib/coccicheck/spatchcache \
SPATCH_FLAGS=--very-quiet
Is cut down from ~20s to ~5s on my system. Much of that is either
fixable shell overhead, or the around 40 files we "CANTCACHE" (see the
implementation).
This uses "redis" as a cache by default, but it's configurable. See
the embedded documentation.
This is *not* like ccache in that we won't cache failed spatch
invocations, or those where spatch suggests changes for us. Those
cases are so rare that I didn't think it was worth the bother, by far
the most common case is that it has no suggested changes. We'll also
refuse to cache any "spatch" invocation that has output on stderr,
which means that "--very-quiet" must be added to "SPATCH_FLAGS".
Because we narrow the cache to that we don't need to save away stdout,
stderr & the exit code. We simply cache the cases where we had no
suggested changes.
Another benchmark is to compare this with the previous
SPATCH_BATCH_SIZE=N, as noted in [1]. Before this (on my 8 core system) running:
make clean; time make contrib/coccinelle/array.cocci.patch SPATCH_BATCH_SIZE=0
Would take 33s, but with the preceding changes running without this
"spatchcache" is slightly slower, or around 35s:
make clean; time make contrib/coccinelle/array.cocci.patch
Now doing the same with SPATCH=contrib/coccinelle/spatchcache will
take around 6s, but we'll need to compile the *.o files first to take
full advantage of it (which can be fast with "ccache"):
make clean; make; time make contrib/coccinelle/array.cocci.patch SPATCH=contrib/coccinelle/spatchcache
1. https://lore.kernel.org/git/YwdRqP1CyUAzCEn2@coredump.intra.peff.net/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public
License version 2 (some parts of it are under different licenses,
compatible with the GPLv2). It was originally written by Linus
Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/
including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
Issues which are security relevant should be disclosed privately to
the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that
list the current status of various development topics to the mailing
list. The discussion following them give a good reference for
project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very
first version. He described the tool as "the stupid content tracker"
and the name as (depending on your mood):
random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
"global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
"goddamn idiotic truckload of sh*t": when it breaks
