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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-02 11:51:02 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-02 11:51:02 -0800 |
commit | 937d6eefc716a9071f0e3bada19200de1bb9d048 (patch) | |
tree | 7b2b8e94d157ddbacc2b0712fd5d20a8b4d79c27 /scripts/jobserver-exec | |
parent | Merge tag 'devicetree-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux (diff) | |
parent | docs: remove a bunch of stray CRs (diff) | |
download | wireguard-linux-937d6eefc716a9071f0e3bada19200de1bb9d048.tar.xz wireguard-linux-937d6eefc716a9071f0e3bada19200de1bb9d048.zip |
Merge tag 'docs-5.5a' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet:
"Here are the main documentation changes for 5.5:
- Various kerneldoc script enhancements.
- More RST conversions; those are slowing down as we run out of
things to convert, but we're a ways from done still.
- Dan's "maintainer profile entry" work landed at last. Now we just
need to get maintainers to fill in the profiles...
- A reworking of the parallel build setup to work better with a
variety of systems (and to not take over huge systems entirely in
particular).
- The MAINTAINERS file is now converted to RST during the build.
Hopefully nobody ever tries to print this thing, or they will need
to load a lot of paper.
- A script and documentation making it easy for maintainers to add
Link: tags at commit time.
Also included is the removal of a bunch of spurious CR characters"
* tag 'docs-5.5a' of git://git.lwn.net/linux: (91 commits)
docs: remove a bunch of stray CRs
docs: fix up the maintainer profile document
libnvdimm, MAINTAINERS: Maintainer Entry Profile
Maintainer Handbook: Maintainer Entry Profile
MAINTAINERS: Reclaim the P: tag for Maintainer Entry Profile
docs, parallelism: Rearrange how jobserver reservations are made
docs, parallelism: Do not leak blocking mode to other readers
docs, parallelism: Fix failure path and add comment
Documentation: Remove bootmem_debug from kernel-parameters.txt
Documentation: security: core.rst: fix warnings
Documentation/process/howto/kokr: Update for 4.x -> 5.x versioning
Documentation/translation: Use Korean for Korean translation title
docs/memory-barriers.txt: Remove remaining references to mmiowb()
docs/memory-barriers.txt/kokr: Update I/O section to be clearer about CPU vs thread
docs/memory-barriers.txt/kokr: Fix style, spacing and grammar in I/O section
Documentation/kokr: Kill all references to mmiowb()
docs/memory-barriers.txt/kokr: Rewrite "KERNEL I/O BARRIER EFFECTS" section
docs: Add initial documentation for devfreq
Documentation: Document how to get links with git am
docs: Add request_irq() documentation
...
Diffstat (limited to 'scripts/jobserver-exec')
-rwxr-xr-x | scripts/jobserver-exec | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec new file mode 100755 index 000000000000..0fdb31a790a8 --- /dev/null +++ b/scripts/jobserver-exec @@ -0,0 +1,66 @@ +#!/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, reserves them all, runs a subprocess +# with PARALLELISM environment variable set, and releases the jobs back again. +# +# https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver +from __future__ import print_function +import os, sys, errno +import subprocess + +# Extract and prepare jobserver file descriptors from envirnoment. +claim = 0 +jobs = b"" +try: + # Fetch the make environment options. + flags = os.environ['MAKEFLAGS'] + + # Look for "--jobserver=R,W" + # Note that GNU Make has used --jobserver-fds and --jobserver-auth + # so this handles all of them. + 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)] + # Open a private copy of reader to avoid setting nonblocking + # on an unexpecting process with the same reader fd. + reader = os.open("/proc/self/fd/%d" % (reader), + os.O_RDONLY | os.O_NONBLOCK) + + # Read out as many jobserver slots as possible. + while True: + try: + slot = os.read(reader, 8) + jobs += slot + except (OSError, IOError) as e: + if e.errno == errno.EWOULDBLOCK: + # Stop at the end of the jobserver queue. + break + # If something went wrong, give back the jobs. + if len(jobs): + os.write(writer, jobs) + raise e + # Add a bump for our caller's reserveration, since we're just going + # to sit here blocked on our child. + claim = len(jobs) + 1 +except (KeyError, IndexError, ValueError, OSError, IOError) as e: + # Any missing environment strings or bad fds should result in just + # not being parallel. + pass + +# We can only claim parallelism if there was a jobserver (i.e. a top-level +# "-jN" argument) and there were no other failures. Otherwise leave out the +# environment variable and let the child figure out what is best. +if claim > 0: + os.environ['PARALLELISM'] = '%d' % (claim) + +rc = subprocess.call(sys.argv[1:]) + +# Return all the reserved slots. +if len(jobs): + os.write(writer, jobs) + +sys.exit(rc) |