diff options
| -rw-r--r-- | Documentation/Makefile | 3 | ||||
| -rwxr-xr-x | scripts/jobserver-count | 58 |
2 files changed, 60 insertions, 1 deletions
diff --git a/Documentation/Makefile b/Documentation/Makefile index e145e4db508b..c6e564656a5b 100644 --- a/Documentation/Makefile +++ b/Documentation/Makefile @@ -33,7 +33,7 @@ ifeq ($(HAVE_SPHINX),0) else # HAVE_SPHINX -export SPHINXOPTS = $(shell perl -e 'open IN,"sphinx-build --version 2>&1 |"; while (<IN>) { if (m/([\d\.]+)/) { print "-jauto" if ($$1 >= "1.7") } ;} close IN') +export SPHINX_PARALLEL = $(shell perl -e 'open IN,"sphinx-build --version 2>&1 |"; while (<IN>) { if (m/([\d\.]+)/) { print "auto" if ($$1 >= "1.7") } ;} close IN') # User-friendly check for pdflatex and latexmk HAVE_PDFLATEX := $(shell if which $(PDFLATEX) >/dev/null 2>&1; then echo 1; else echo 0; fi) @@ -68,6 +68,7 @@ quiet_cmd_sphinx = SPHINX $@ --> file://$(abspath $(BUILDDIR)/$3/$4) PYTHONDONTWRITEBYTECODE=1 \ BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \ $(SPHINXBUILD) \ + -j $(shell python $(srctree)/scripts/jobserver-count $(SPHINX_PARALLEL)) \ -b $2 \ -c $(abspath $(srctree)/$(src)) \ -d $(abspath $(BUILDDIR)/.doctrees/$3) \ diff --git a/scripts/jobserver-count b/scripts/jobserver-count new file mode 100755 index 000000000000..0b482d6884d2 --- /dev/null +++ b/scripts/jobserver-count @@ -0,0 +1,58 @@ +#!/usr/bin/env python +# SPDX-License-Identifier: GPL-2.0+ +# +# This determines how many parallel tasks "make" is expecting, as it is +# not exposed via an special variables. +# https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver +from __future__ import print_function +import os, sys, fcntl, errno + +# Default parallelism is "1" unless overridden on the command-line. +default="1" +if len(sys.argv) > 1: + default=sys.argv[1] + +# Set non-blocking for a given file descriptor. +def nonblock(fd): + flags = fcntl.fcntl(fd, fcntl.F_GETFL) + fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) + return fd + +# Extract and prepare jobserver file descriptors from envirnoment. +try: + # Fetch the make environment options. + flags = os.environ['MAKEFLAGS'] + + # Look for "--jobserver=R,W" + opts = [x for x in flags.split(" ") if x.startswith("--jobserver")] + + # Parse out R,W file descriptor numbers and set them nonblocking. + fds = opts[0].split("=", 1)[1] + reader, writer = [int(x) for x in fds.split(",", 1)] + reader = nonblock(reader) +except (KeyError, IndexError, ValueError, IOError): + # Any missing environment strings or bad fds should result in just + # using the default specified parallelism. + print(default) + sys.exit(0) + +# Read out as many jobserver slots as possible. +jobs = b"" +while True: + try: + slot = os.read(reader, 1) + jobs += slot + except (OSError, IOError) as e: + if e.errno == errno.EWOULDBLOCK: + # Stop when reach the end of the jobserver queue. + break + raise e +# Return all the reserved slots. +os.write(writer, jobs) + +# If the jobserver was (impossibly) full or communication failed, use default. +if len(jobs) < 1: + print(default) + +# Report available slots (with a bump for our caller's reserveration). +print(len(jobs) + 1) |