mirror of
https://github.com/MariaDB/server.git
synced 2025-01-30 18:41:56 +01:00
277ba134ad
Typically, index_lock and fil_space_t::latch will be held for a longer time than the spin loop in latch acquisition would be waiting for. Let us avoid spin loops for those as well as dict_sys.latch, which could be held in exclusive mode for a longer time (while loading metadata into the buffer pool and the dictionary cache). Performance testing on a dual Intel Xeon E5-2630 v4 (2 NUMA nodes) suggests that the buffer pool page latch (block_lock) benefits from a spin loop in both read-only and read-write workloads where the working set is slightly larger than the buffer pool. Presumably, most contention would occur on leaf page latches. Contention on upper level pages in the buffer pool should intuitively last longer. We introduce srw_spin_lock and srw_spin_mutex to allow users of srw_lock or srw_mutex to opt in for the spin loop. On Microsoft Windows, a spin loop variant was and will not be available; srw_mutex and srw_lock will simply wrap SRWLOCK. That is, on Microsoft Windows, the parameters innodb_sync_spin_loops and innodb_spin_wait_delay will only affect block_lock.
185 lines
3.5 KiB
C++
185 lines
3.5 KiB
C++
/* Copyright (c) 2021, MariaDB Corporation.
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License as
|
|
published by the Free Software Foundation; version 2 of the License.
|
|
|
|
This program is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
|
|
|
|
#include <thread>
|
|
#include "tap.h"
|
|
#include "my_sys.h"
|
|
#include "sux_lock.h"
|
|
|
|
static std::atomic<bool> critical;
|
|
|
|
ulong srv_n_spin_wait_rounds= 30;
|
|
uint srv_spin_wait_delay= 4;
|
|
|
|
constexpr unsigned N_THREADS= 30;
|
|
constexpr unsigned N_ROUNDS= 100;
|
|
constexpr unsigned M_ROUNDS= 100;
|
|
|
|
static srw_mutex m;
|
|
|
|
static void test_srw_mutex()
|
|
{
|
|
for (auto i= N_ROUNDS * M_ROUNDS; i--; )
|
|
{
|
|
m.wr_lock();
|
|
assert(!critical);
|
|
critical= true;
|
|
critical= false;
|
|
m.wr_unlock();
|
|
}
|
|
}
|
|
|
|
static srw_lock_low l;
|
|
|
|
static void test_srw_lock()
|
|
{
|
|
for (auto i= N_ROUNDS; i--; )
|
|
{
|
|
l.wr_lock();
|
|
assert(!critical);
|
|
critical= true;
|
|
critical= false;
|
|
l.wr_unlock();
|
|
|
|
for (auto j= M_ROUNDS; j--; )
|
|
{
|
|
l.rd_lock();
|
|
assert(!critical);
|
|
l.rd_unlock();
|
|
}
|
|
}
|
|
}
|
|
|
|
static ssux_lock_impl<false> ssux;
|
|
|
|
static void test_ssux_lock()
|
|
{
|
|
for (auto i= N_ROUNDS; i--; )
|
|
{
|
|
ssux.wr_lock();
|
|
assert(!critical);
|
|
critical= true;
|
|
critical= false;
|
|
ssux.wr_unlock();
|
|
|
|
for (auto j= M_ROUNDS; j--; )
|
|
{
|
|
ssux.rd_lock();
|
|
assert(!critical);
|
|
ssux.rd_unlock();
|
|
}
|
|
|
|
for (auto j= M_ROUNDS; j--; )
|
|
{
|
|
ssux.u_lock();
|
|
assert(!critical);
|
|
ssux.u_wr_upgrade();
|
|
assert(!critical);
|
|
critical= true;
|
|
critical= false;
|
|
ssux.wr_u_downgrade();
|
|
ssux.u_unlock();
|
|
}
|
|
}
|
|
}
|
|
|
|
static sux_lock<ssux_lock_impl<true>> sux;
|
|
|
|
static void test_sux_lock()
|
|
{
|
|
for (auto i= N_ROUNDS; i--; )
|
|
{
|
|
sux.x_lock();
|
|
assert(!critical);
|
|
critical= true;
|
|
for (auto j= M_ROUNDS; j--; )
|
|
sux.x_lock();
|
|
critical= false;
|
|
for (auto j= M_ROUNDS + 1; j--; )
|
|
sux.x_unlock();
|
|
|
|
for (auto j= M_ROUNDS; j--; )
|
|
{
|
|
sux.s_lock();
|
|
assert(!critical);
|
|
sux.s_unlock();
|
|
}
|
|
|
|
for (auto j= M_ROUNDS / 2; j--; )
|
|
{
|
|
sux.u_lock();
|
|
assert(!critical);
|
|
sux.u_lock();
|
|
sux.u_x_upgrade();
|
|
assert(!critical);
|
|
critical= true;
|
|
sux.x_unlock();
|
|
critical= false;
|
|
sux.x_u_downgrade();
|
|
sux.u_unlock();
|
|
}
|
|
}
|
|
}
|
|
|
|
int main(int argc __attribute__((unused)), char **argv)
|
|
{
|
|
std::thread t[N_THREADS];
|
|
|
|
MY_INIT(argv[0]);
|
|
|
|
plan(4);
|
|
|
|
m.init();
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i]= std::thread(test_srw_mutex);
|
|
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i].join();
|
|
|
|
m.destroy();
|
|
ok(true, "srw_mutex");
|
|
|
|
l.init();
|
|
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i]= std::thread(test_srw_lock);
|
|
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i].join();
|
|
|
|
ok(true, "srw_lock");
|
|
|
|
l.destroy();
|
|
|
|
ssux.init();
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i]= std::thread(test_ssux_lock);
|
|
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i].join();
|
|
|
|
ok(true, "ssux_lock");
|
|
ssux.destroy();
|
|
|
|
sux.init();
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i]= std::thread(test_sux_lock);
|
|
|
|
for (auto i= N_THREADS; i--; )
|
|
t[i].join();
|
|
|
|
ok(true, "sux_lock");
|
|
sux.free();
|
|
}
|