But now include a check for CPU_COUNT so we still build on 10 year old
versions of glibc.
Original message:
Use sched_getaffinity instead of std:🧵:hardware_concurrency.
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.
With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.
This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.
llvm-svn: 314931
Summary:
This reverts D38481. The change breaks systems with older versions of glibc. It
injects a use of CPU_COUNT() from sched.h without checking to ensure that the
function exists first.
Reviewers:
Subscribers:
llvm-svn: 314922
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.
With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.
This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.
llvm-svn: 314809
Prior to MSVC 2015 we had to manually include this header any
time we were going to include <thread> or <future> due to a
bug in MSVC's STL implementation. This has been fixed in MSVC
for some time now, and we require VS 2015 minimum, so we can
remove this across all subprojects.
llvm-svn: 296906
Summary:
Apparently, when compiling with gcc 5.3.2 for powerpc64, the order of
headers is such that it gets an error about std::atomic<> use in
ThreadPool.h, since this header is not included explicitly. See also:
https://llvm.org/bugs/show_bug.cgi?id=27058
Fix this by including <atomic>. Patch by Bryan Drewery.
Reviewers: chandlerc, joker.eph
Subscribers: bdrewery, llvm-commits
Differential Revision: http://reviews.llvm.org/D18460
llvm-svn: 264335
Eventually we may need to sink this include to the .cpp file or
something to suport LLVM_ENABLE_THREADS=OFF, but this solves my
immediate problem of fixing the build.
llvm-svn: 255682
This is a very simple implementation of a thread pool using C++11
thread. It accepts any std::function<void()> for asynchronous
execution. Individual task can be synchronize using the returned
future, or the client can block on the full queue completion.
In case LLVM is configured with Threading disabled, it falls back
to sequential execution using std::async with launch:deferred.
This is intended to support parallelism for ThinLTO processing in
linker plugin, but is generic enough for any other uses.
This is a recommit of r255444 ; trying to workaround a bug in the
MSVC 2013 standard library. I think I was hit by:
http://connect.microsoft.com/VisualStudio/feedbackdetail/view/791185/std-packaged-task-t-where-t-is-void-or-a-reference-class-are-not-movable
Recommit of r255589, trying to please g++ as well.
Differential Revision: http://reviews.llvm.org/D15464
From: mehdi_amini <mehdi_amini@91177308-0d34-0410-b5e6-96231b3b80d8>
llvm-svn: 255593
This is a very simple implementation of a thread pool using C++11
thread. It accepts any std::function<void()> for asynchronous
execution. Individual task can be synchronize using the returned
future, or the client can block on the full queue completion.
In case LLVM is configured with Threading disabled, it falls back
to sequential execution using std::async with launch:deferred.
This is intended to support parallelism for ThinLTO processing in
linker plugin, but is generic enough for any other uses.
This is a recommit of r255444 ; trying to workaround a bug in the
MSVC 2013 standard library. I think I was hit by:
http://connect.microsoft.com/VisualStudio/feedbackdetail/view/791185/std-packaged-task-t-where-t-is-void-or-a-reference-class-are-not-movable
Differential Revision: http://reviews.llvm.org/D15464
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 255589
This is a very simple implementation of a thread pool using C++11
thread. It accepts any std::function<void()> for asynchronous
execution. Individual task can be synchronize using the returned
future, or the client can block on the full queue completion.
In case LLVM is configured with Threading disabled, it falls back
to sequential execution using std::async with launch:deferred.
This is intended to support parallelism for ThinLTO processing in
linker plugin, but is generic enough for any other uses.
Differential Revision: http://reviews.llvm.org/D15464
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 255444
