##// END OF EJS Templates
merge: mark file gets as not thread safe (issue5933)...
merge: mark file gets as not thread safe (issue5933) In default installs, this has the effect of disabling the thread-based worker on Windows when manifesting files in the working directory. My measurements have shown that with revlog-based repositories, Mercurial spends a lot of CPU time in revlog code resolving file data. This ends up incurring a lot of context switching across threads and slows down `hg update` operations when going from an empty working directory to the tip of the repo. On mozilla-unified (246,351 files) on an i7-6700K (4+4 CPUs): before: 487s wall after: 360s wall (equivalent to worker.enabled=false) cpus=2: 379s wall Even with only 2 threads, the thread pool is still slower. The introduction of the thread-based worker (02b36e860e0b) states that it resulted in a "~50%" speedup for `hg sparse --enable-profile` and `hg sparse --disable-profile`. This disagrees with my measurement above. I theorize a few reasons for this: 1) Removal of files from the working directory is I/O - not CPU - bound and should benefit from a thread pool (unless I/O is insanely fast and the GIL release is near instantaneous). So tests like `hg sparse --enable-profile` may exercise deletion throughput and aren't good benchmarks for worker tasks that are CPU heavy. 2) The patch was authored by someone at Facebook. The results were likely measured against a repository using remotefilelog. And I believe that revision retrieval during working directory updates with remotefilelog will often use a remote store, thus being I/O and not CPU bound. This probably resulted in an overstated performance gain. Since there appears to be a need to enable the thread-based worker with some stores, I've made the flagging of file gets as thread safe configurable. I've made it experimental because I don't want to formalize a boolean flag for this option and because this attribute is best captured against the store implementation. But we don't have a proper store API for this yet. I'd rather cross this bridge later. It is possible there are revlog-based repositories that do benefit from a thread-based worker. I didn't do very comprehensive testing. If there are, we may want to devise a more proper algorithm for whether to use the thread-based worker, including possibly config options to limit the number of threads to use. But until I see evidence that justifies complexity, simplicity wins. Differential Revision: https://phab.mercurial-scm.org/D3963

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setup_zstd.py
160 lines | 4.4 KiB | text/x-python | PythonLexer
# Copyright (c) 2016-present, Gregory Szorc
# All rights reserved.
#
# This software may be modified and distributed under the terms
# of the BSD license. See the LICENSE file for details.
import distutils.ccompiler
import os
import sys
from distutils.extension import Extension
zstd_sources = ['zstd/%s' % p for p in (
'common/entropy_common.c',
'common/error_private.c',
'common/fse_decompress.c',
'common/pool.c',
'common/threading.c',
'common/xxhash.c',
'common/zstd_common.c',
'compress/fse_compress.c',
'compress/huf_compress.c',
'compress/zstd_compress.c',
'compress/zstd_double_fast.c',
'compress/zstd_fast.c',
'compress/zstd_lazy.c',
'compress/zstd_ldm.c',
'compress/zstd_opt.c',
'compress/zstdmt_compress.c',
'decompress/huf_decompress.c',
'decompress/zstd_decompress.c',
'dictBuilder/cover.c',
'dictBuilder/divsufsort.c',
'dictBuilder/zdict.c',
)]
zstd_sources_legacy = ['zstd/%s' % p for p in (
'deprecated/zbuff_common.c',
'deprecated/zbuff_compress.c',
'deprecated/zbuff_decompress.c',
'legacy/zstd_v01.c',
'legacy/zstd_v02.c',
'legacy/zstd_v03.c',
'legacy/zstd_v04.c',
'legacy/zstd_v05.c',
'legacy/zstd_v06.c',
'legacy/zstd_v07.c'
)]
zstd_includes = [
'zstd',
'zstd/common',
'zstd/compress',
'zstd/decompress',
'zstd/dictBuilder',
]
zstd_includes_legacy = [
'zstd/deprecated',
'zstd/legacy',
]
ext_includes = [
'c-ext',
'zstd/common',
]
ext_sources = [
'zstd/common/pool.c',
'zstd/common/threading.c',
'zstd.c',
'c-ext/bufferutil.c',
'c-ext/compressiondict.c',
'c-ext/compressobj.c',
'c-ext/compressor.c',
'c-ext/compressoriterator.c',
'c-ext/compressionparams.c',
'c-ext/compressionreader.c',
'c-ext/compressionwriter.c',
'c-ext/constants.c',
'c-ext/decompressobj.c',
'c-ext/decompressor.c',
'c-ext/decompressoriterator.c',
'c-ext/decompressionreader.c',
'c-ext/decompressionwriter.c',
'c-ext/frameparams.c',
]
zstd_depends = [
'c-ext/python-zstandard.h',
]
def get_c_extension(support_legacy=False, system_zstd=False, name='zstd',
warnings_as_errors=False):
"""Obtain a distutils.extension.Extension for the C extension."""
root = os.path.abspath(os.path.dirname(__file__))
sources = set([os.path.join(root, p) for p in ext_sources])
if not system_zstd:
sources.update([os.path.join(root, p) for p in zstd_sources])
if support_legacy:
sources.update([os.path.join(root, p) for p in zstd_sources_legacy])
sources = list(sources)
include_dirs = set([os.path.join(root, d) for d in ext_includes])
if not system_zstd:
include_dirs.update([os.path.join(root, d) for d in zstd_includes])
if support_legacy:
include_dirs.update([os.path.join(root, d) for d in zstd_includes_legacy])
include_dirs = list(include_dirs)
depends = [os.path.join(root, p) for p in zstd_depends]
compiler = distutils.ccompiler.new_compiler()
# Needed for MSVC.
if hasattr(compiler, 'initialize'):
compiler.initialize()
if compiler.compiler_type == 'unix':
compiler_type = 'unix'
elif compiler.compiler_type == 'msvc':
compiler_type = 'msvc'
elif compiler.compiler_type == 'mingw32':
compiler_type = 'mingw32'
else:
raise Exception('unhandled compiler type: %s' %
compiler.compiler_type)
extra_args = ['-DZSTD_MULTITHREAD']
if not system_zstd:
extra_args.append('-DZSTDLIB_VISIBILITY=')
extra_args.append('-DZDICTLIB_VISIBILITY=')
extra_args.append('-DZSTDERRORLIB_VISIBILITY=')
if compiler_type == 'unix':
extra_args.append('-fvisibility=hidden')
if not system_zstd and support_legacy:
extra_args.append('-DZSTD_LEGACY_SUPPORT=1')
if warnings_as_errors:
if compiler_type in ('unix', 'mingw32'):
extra_args.append('-Werror')
elif compiler_type == 'msvc':
extra_args.append('/WX')
else:
assert False
libraries = ['zstd'] if system_zstd else []
# TODO compile with optimizations.
return Extension(name, sources,
include_dirs=include_dirs,
depends=depends,
extra_compile_args=extra_args,
libraries=libraries)