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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314931 91177308-0d34-0410-b5e6-96231b3b80d8
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:
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314922 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314809 91177308-0d34-0410-b5e6-96231b3b80d8
Applications often need the current thread id when making
system calls, and some operating systems provide the notion
of a thread name, which can be useful in enabling better
diagnostics when debugging or logging.
This patch adds an accessor for the thread id, and "best effort"
getters and setters for the thread name. Since this is
non critical functionality, no error is returned to indicate
that a platform doesn't support thread names.
Differential Revision: https://reviews.llvm.org/D30526
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296887 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we could not use it because std::once_flag's default
constructor was not constexpr. Today, all supported versions of VS
correctly mark it constexpr. I confirmed that MSVC 2015 does not emit
any problematic racy dynamic initialization code, so we should be safe
to use this now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295013 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Make this interface reusable similarly to std::call_once and std::once_flag interface.
This makes porting LLDB to NetBSD easier as there was in the original approach a portable way to specify a non-static once_flag. With this change translating std::once_flag to llvm::once_flag is mechanical.
Sponsored by <The NetBSD Foundation>
Reviewers: mehdi_amini, labath, joerg
Reviewed By: mehdi_amini
Subscribers: emaste, clayborg
Differential Revision: https://reviews.llvm.org/D29566
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294143 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently users need to set call `using namespace llvm;`, with this change it's no longer needed.
Sponsored by <The NetBSD Foundation>
Reviewers: labath, emaste, joerg, clayborg, mehdi_amini
Reviewed By: mehdi_amini
Subscribers: chandlerc
Differential Revision: https://reviews.llvm.org/D29296
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293902 91177308-0d34-0410-b5e6-96231b3b80d8
It was noticed this caused performance regressions and deadlocks. PR30768.
Reorder the code to make it clearer what is tested.
PPC now disables the use of std::call_once only with libstdc++ with
the reordering of the code, as was the original intent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285782 91177308-0d34-0410-b5e6-96231b3b80d8
Based on post-commit review for D25585/r284180, rename
hardware_physical_concurrency to heavyweight_hardware_concurrency,
to better reflect what type of tasks it should be used for and
to enable other systems to map this to something other than the
number of physical cores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284390 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This will be used by ThinLTO to set the amount of backend
parallelism, which performs better when restricted to the number
of physical cores (on X86 at least, where getHostNumPhysicalCores is
currently defined). If not available this falls back to
thread::hardware_concurrency.
Note I didn't add to the thread class since that is a typedef to
std::thread where available.
Reviewers: mehdi_amini
Subscribers: beanz, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D25585
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284180 91177308-0d34-0410-b5e6-96231b3b80d8
libstdc++ (or in compilers, or somewhere, I can't track it down) that
causes unittests that use INITIALIZE_PASS to crash.
The analysis I've been able to do is that inside libstdc++'s
implementation of std::call_once, it uses pthread_once, and when that
returns an error code it throws std::system_error which then eventually
calls std::terminate.
Hopefully some of the folks who work on PPC can try to sort out what's
going on here. Until then, they'll have to use the fallback
implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271821 91177308-0d34-0410-b5e6-96231b3b80d8
CALL_ONCE_... macro in the legacy pass manager with the new
llvm::call_once facility.
Nothing changed sicne the last attempt in r271781 which I reverted in
r271788. At least one of the failures I saw was spurious, and I want to
make sure the other failures are real before I work around them -- they
appeared to only effect ppc64le and ppc64be.
Original commit message of r271781:
----
[LPM] Reinstate r271652 to replace the CALL_ONCE_... macro in the legacy
pass manager with the new llvm::call_once facility.
This reverts commit r271657 and re-applies r271652 with a fix to
actually work with arguments. In the original version, we just ended up
directly calling std::call_once via ADL because of the std::once_flag
argument. The llvm::call_once never worked with arguments. Now,
llvm::call_once is a variadic template that perfectly forwards
everything. As a part of this it had to move to the header and we use
a generic functor rather than an explict function pointer. It would be
nice to use std::invoke here but we don't have it yet. That means
pointer to members won't work here, but that seems a tolerable
compromise.
I've also tested this by forcing the fallback path, so hopefully it
sticks this time.
----
Original commit message of r271652:
----
[LPM] Replace the CALL_ONCE_... macro in the legacy pass manager with
the new llvm::call_once facility.
This facility matches the standard APIs and when the platform supports
it actually directly uses the standard provided functionality. This is
both more efficient on some platforms and much more TSan friendly.
The only remaining user of the cas_flag and home-rolled atomics is the
fallback implementation of call_once. I have a patch that removes them
entirely, but it needs a Windows patch to land first.
This alone substantially cleans up the macros for the legacy pass
manager, and should subsume some of the work Mehdi was doing to clear
the path for TSan testing of ThinLTO, a really important step to have
reliable upstream testing of ThinLTO in all forms.
----
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271800 91177308-0d34-0410-b5e6-96231b3b80d8
There appears to be a strange exception thrown and crash using call_once
on a PPC build bot, and a *really* weird windows link error for
GCMetadata.obj. Still need to investigate the cause of both problems.
Original change summary:
[LPM] Reinstate r271652 to replace the CALL_ONCE_... macro in the legacy
pass manager with the new llvm::call_once facility.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271788 91177308-0d34-0410-b5e6-96231b3b80d8
pass manager with the new llvm::call_once facility.
This reverts commit r271657 and re-applies r271652 with a fix to
actually work with arguments. In the original version, we just ended up
directly calling std::call_once via ADL because of the std::once_flag
argument. The llvm::call_once never worked with arguments. Now,
llvm::call_once is a variadic template that perfectly forwards
everything. As a part of this it had to move to the header and we use
a generic functor rather than an explict function pointer. It would be
nice to use std::invoke here but we don't have it yet. That means
pointer to members won't work here, but that seems a tolerable
compromise.
I've also tested this by forcing the fallback path, so hopefully it
sticks this time.
Original commit message:
----
[LPM] Replace the CALL_ONCE_... macro in the legacy pass manager with
the new llvm::call_once facility.
This facility matches the standard APIs and when the platform supports
it actually directly uses the standard provided functionality. This is
both more efficient on some platforms and much more TSan friendly.
The only remaining user of the cas_flag and home-rolled atomics is the
fallback implementation of call_once. I have a patch that removes them
entirely, but it needs a Windows patch to land first.
This alone substantially cleans up the macros for the legacy pass
manager, and should subsume some of the work Mehdi was doing to clear
the path for TSan testing of ThinLTO, a really important step to have
reliable upstream testing of ThinLTO in all forms.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271781 91177308-0d34-0410-b5e6-96231b3b80d8
D19271.
Previous attempt was broken by NetBSD, so in this version I've made the
fallback path generic rather than Windows specific and sent both Windows
and NetBSD to it.
I've also re-formatted the code some, and used an exact clone of the
code in PassSupport.h for doing manual call-once using our atomics
rather than rolling a new one.
If this sticks, we can replace the fallback path for Windows with
a Windows-specific implementation that is more reliable.
Original commit message:
This patch adds an llvm_call_once which is a wrapper around
std::call_once on platforms where it is available and devoid
of bugs. The patch also migrates the ManagedStatic mutex to
be allocated using llvm_call_once.
These changes are philosophically equivalent to the changes
added in r219638, which were reverted due to a hang on Win32
which was the result of a bug in the Windows implementation
of std::call_once.
Differential Revision: http://reviews.llvm.org/D5922
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271558 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r221331 and reinstate r220932 as discussed in D19271.
Original commit message was:
This patch adds an llvm_call_once which is a wrapper around
std::call_once on platforms where it is available and devoid
of bugs. The patch also migrates the ManagedStatic mutex to
be allocated using llvm_call_once.
These changes are philosophically equivalent to the changes
added in r219638, which were reverted due to a hang on Win32
which was the result of a bug in the Windows implementation
of std::call_once.
Differential Revision: http://reviews.llvm.org/D5922
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269577 91177308-0d34-0410-b5e6-96231b3b80d8
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
Commit 220932 caused crash when building clang-tblgen on aarch64 debian target,
so it's blocking all daily tests.
The std::call_once implementation in pthread has bug for aarch64 debian.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221331 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch adds an llvm_call_once which is a wrapper around std::call_once on platforms where it is available and devoid of bugs. The patch also migrates the ManagedStatic mutex to be allocated using llvm_call_once.
These changes are philosophically equivalent to the changes added in r219638, which were reverted due to a hang on Win32 which was the result of a bug in the Windows implementation of std::call_once.
Reviewers: aaron.ballman, chapuni, chandlerc, rnk
Reviewed By: rnk
Subscribers: majnemer, llvm-commits
Differential Revision: http://reviews.llvm.org/D5922
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220932 91177308-0d34-0410-b5e6-96231b3b80d8
This goes with the earlier commit to remove the static destructor from ManagedStatic.cpp by controlling the allocation and de-allocation of the mutex.
Summary: This is part of the ongoing work to remove static constructors and destructors.
Reviewers: chandlerc, rnk
Reviewed By: rnk
Subscribers: rnk, llvm-commits
Differential Revision: http://reviews.llvm.org/D5473
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219640 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds a new llvm_call_once function which is used by the ManagedStatic implementation to safely initialize a global to avoid static construction and destruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219638 91177308-0d34-0410-b5e6-96231b3b80d8
I'll fix the problems in libclang and other projects in ways that don't
require <mutex> until we sort out the cygwin situation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211900 91177308-0d34-0410-b5e6-96231b3b80d8
After a number of previous small iterations, the functions
llvm_start_multithreaded() and llvm_stop_multithreaded() have
been reduced essentially to no-ops. This change removes them
entirely.
Reviewed by: rnk, dblaikie
Differential Revision: http://reviews.llvm.org/D4216
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211287 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes the LLVM global lock, and updates all existing
users of the global lock to use their own mutex. None of the
existing users of the global lock were protecting code that was
mutually exclusive with any of the other users of the global
lock, so its purpose was not being met.
Reviewed by: rnk
Differential Revision: http://reviews.llvm.org/D4142
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211277 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes the functions llvm_start_multithreaded() and
llvm_stop_multithreaded(), and changes llvm_is_multithreaded()
to return a constant value based on the value of the compile-time
definition LLVM_ENABLE_THREADS.
Previously, it was possible to have compile-time support for
threads on, and runtime support for threads off, in which case
certain mutexes were not allocated or ever acquired. Now, if the
build is created with threads enabled, mutexes are always acquired.
A test before/after patch of compiling a very large TU showed no
noticeable performance impact of this change.
Reviewers: rnk
Differential Revision: http://reviews.llvm.org/D4076
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210600 91177308-0d34-0410-b5e6-96231b3b80d8
* wrap code blocks in \code ... \endcode;
* refer to parameter names in paragraphs correctly (\arg is not what most
people want -- it starts a new paragraph).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163790 91177308-0d34-0410-b5e6-96231b3b80d8
