Improve remote dealloc
- Outline the slow path to improve code gen significantly
- Handle message queue only on slow path for remote dealloc.
- Change remote size to count down 0, so fast path does not need a constant.
- Use signed value so that branch does not depend on addition.
The bootstrapping allocator needs to perform a memcpy to bypass the
removed move constructors on std::atomic. This is safe as there is no
concurrency at this point, but GCC is unhappy with this.
This commit moves CI to GCC8 and disables this warning for that line.
On platforms that support low-memory notifications register callbacks
that perform lazy decommit. This allows idle processes to return memory
to the OS. Without incurring the cost of constantly committing and
decommitting memory.
Code review and CI changes
* Fixed test to use a template to make constexpr magic work
* Factored out basic notification mechanism so can be reused on other
platforms.
If the external thread statics are used, then
we don't need to include some C++ runtime
concepts. This refactoring moves some global initialization under
conditional compilation.
Windows is only sending low-memory notifications when the machine
is reaching low-memory. So running a 32bit process on 64bit machine
can easily exhaust address space before machine gets close to
low-memory.
The low-memory notification was getting into an infinite loop. This
fixes the loop termination, and provides a test for platforms which
support low-memory notification.
On platforms that do not support aligned mmap/VirtualAlloc,
we need to produce heavily aligned blocks to guarantee we can meet
all possible alignment requests.
This commit grabs a block much larger than requested, and then produces
"offcuts" before and after the block of smaller/same "large_classes". This
enables one mmap/virtual alloc request to services many other requests
for aligned memory.
The PAL API previously allowed for returning more memory than asked for.
This was when the PAL performed the alignment work, now this is done in
large alloc, so removing from the PAL.
* Removing option as not supported by CI
Will migrate CI forward and readd.
* Made failure for clang-format errors.
* Improved handling of errors during CI.
* Prevent failures escaping.
* Clang-format fix
* Remove stderr
* Update azure-pipelines.yml
Co-Authored-By: Paul Liétar <plietar@users.noreply.github.com>
Co-authored-by: Paul Liétar <plietar@users.noreply.github.com>
The performance on Windows was significantly regressed by the
notify_using during the bump allocation. This change removes that.
It appears that the pages are already committed by
the large allocator.
