Introduce special synchronization primitive group_commit_lock
for more efficient synchronization of redo log writing and flushing.
The goal is to reduce CPU consumption on log_write_up_to, to reduce
the spurious wakeups, and improve the throughput in write-intensive
benchmarks.
Detecting the cpus based on sysconf of the online CPUs can significantly
over estimate the number of cpus available.
Wheither via numactl, cgroups, taskset, systemd constraints, docker
containers and probably other mechanisms, the number of threads mysqld
can be run on can be quite less.
As such we use the pthread_getaffinity_np function on Linux and FreeBSD
(identical API) to get the number of CPUs.
The number of CPUs is the default for the thread_pool_size and a too
high default will resulting in large memory usage and high context
switching overhead.
Closes PR #922
The fix consists of three commits backported from 10.3:
1) Cleanup isnan() portability checks
(cherry picked from commit 7ffd7fe962)
2) Cleanup isinf() portability checks
Original problem reported by Wlad: re-compilation of 10.3 on top of 10.2
build would cache undefined HAVE_ISINF from 10.2, whereas it is expected
to be 1 in 10.3.
std::isinf() seem to be available on all supported platforms.
(cherry picked from commit bc469a0bdf)
3) Use std::isfinite in C++ code
This is addition to parent revision fixing build failures.
(cherry picked from commit 54999f4e75)
Fix build error with newer cmake
Fixes the following build error:
CMake Error at cmake/os/Linux.cmake:29 (STRING):
STRING sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
CMakeLists.txt:101 (INCLUDE)
CMake Error at cmake/os/Linux.cmake:29 (STRING):
STRING sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
CMakeLists.txt:101 (INCLUDE)
The error happens when CMAKE_SHARED_LINKER_{LANG}_FLAGS is not set.
Force the variable to be set to "" as input to prevent this.
Signed-off-by: Ryan Coe <bluemrp9@gmail.com>
Signed-off-by: Vicențiu Ciorbaru <vicentiu@mariadb.org>
On clang, use __builtin_readcyclecounter() when available.
Hinted by Sergey Vojtovich. (This may lead to runtime failure
on ARM systems. The hardware should be available on ARMv8 (AArch64),
but access to it may require special privileges.)
We remove support for the proprietary Sun Microsystems compiler,
and rely on clang or the __GNUC__ assembler syntax instead.
For now, we retain support for IA-64 (Itanium) and 32-bit SPARC,
even though those platforms are likely no longer widely used.
We remove support for clock_gettime(CLOCK_SGI_CYCLE),
because Silicon Graphics ceased supporting IRIX in December 2013.
This was the only cycle timer interface available for MIPS.
On PowerPC, we rely on the GCC 4.8 __builtin_ppc_get_timebase()
(or clang __builtin_readcyclecounter()), which should be equivalent
to the old assembler code on both 64-bit and 32-bit targets.
Improve previous patch so we do not depend on (tiny) compiler-version
dependent libraries, i.e vcruntime140.dll, and msvcp140.dll
The remaining dependency is Universal CRT, is part of Win10+ OS,
and should already be installed by Windows update on most downlevel
systems.
SIGHUP causes debug info in the error log and reload of
logs/privileges/tables/etc. The server should only do it when
a user intentionally sends SUGHUP, not when a parent terminal gets
disconnected or something.
In particular, not ignoring kernel SIGHUP causes FLUSH PRIVILEGES
at some random point during non-systemd Debian upgrades (Debian
restarts mysqld, debian-start script runs mysql_upgrade in the background,
postinit script ends and kernel sends SIGHUP to all background processes
it has started). And during mysql_upgrade privilege tables aren't
necessarily ready to be reloaded.
main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
