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df563e0c03
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.
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
#ifndef MY_CPU_INCLUDED
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#define MY_CPU_INCLUDED
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/* Copyright (c) 2013, MariaDB foundation Ab and SkySQL
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1301 USA
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*/
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/* instructions for specific cpu's */
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/*
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Macros for adjusting thread priority (hardware multi-threading)
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The defines are the same ones used by the linux kernel
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*/
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#ifdef _ARCH_PWR8
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#include <sys/platform/ppc.h>
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/* Very low priority */
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#define HMT_very_low() __ppc_set_ppr_very_low()
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/* Low priority */
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#define HMT_low() __ppc_set_ppr_low()
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/* Medium low priority */
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#define HMT_medium_low() __ppc_set_ppr_med_low()
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/* Medium priority */
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#define HMT_medium() __ppc_set_ppr_med()
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/* Medium high priority */
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#define HMT_medium_high() __ppc_set_ppr_med_high()
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/* High priority */
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#define HMT_high() asm volatile("or 3,3,3")
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#else
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#define HMT_very_low()
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#define HMT_low()
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#define HMT_medium_low()
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#define HMT_medium()
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#define HMT_medium_high()
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#define HMT_high()
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#endif
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static inline void MY_RELAX_CPU(void)
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{
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#ifdef HAVE_PAUSE_INSTRUCTION
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/*
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According to the gcc info page, asm volatile means that the
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instruction has important side-effects and must not be removed.
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Also asm volatile may trigger a memory barrier (spilling all registers
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to memory).
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*/
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#ifdef __SUNPRO_CC
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asm ("pause" );
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#else
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__asm__ __volatile__ ("pause");
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#endif
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#elif defined(HAVE_FAKE_PAUSE_INSTRUCTION)
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__asm__ __volatile__ ("rep; nop");
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#elif defined _WIN32
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/*
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In the Win32 API, the x86 PAUSE instruction is executed by calling
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the YieldProcessor macro defined in WinNT.h. It is a CPU architecture-
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independent way by using YieldProcessor.
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*/
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YieldProcessor();
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#elif defined(_ARCH_PWR8)
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__ppc_get_timebase();
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#else
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int32 var, oldval = 0;
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my_atomic_cas32_strong_explicit(&var, &oldval, 1, MY_MEMORY_ORDER_RELAXED,
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MY_MEMORY_ORDER_RELAXED);
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#endif
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}
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/*
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LF_BACKOFF should be used to improve performance on hyperthreaded CPUs. Intel
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recommends to use it in spin loops also on non-HT machines to reduce power
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consumption (see e.g http://softwarecommunity.intel.com/articles/eng/2004.htm)
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Running benchmarks for spinlocks implemented with InterlockedCompareExchange
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and YieldProcessor shows that much better performance is achieved by calling
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YieldProcessor in a loop - that is, yielding longer. On Intel boxes setting
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loop count in the range 200-300 brought best results.
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*/
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static inline int LF_BACKOFF(void)
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{
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int i;
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for (i= 0; i < 200; i++)
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MY_RELAX_CPU();
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return 1;
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}
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#endif
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