kernel_optimize_test/arch/mips/include/asm/fpu_emulator.h
David Daney b6ee75ed4f MIPS: Collect FPU emulator statistics per-CPU.
On SMP systems, the collection of statistics can cause cache line
bouncing in the lines associated with the counters.  Also there are
races incrementing the counters on multiple CPUs.

To fix both problems, we collect the statistics in per-CPU variables,
and add them up in the debugfs read operation.

As a test I ran the LTP float_bessel test on a 12 CPU Octeon system.

Without CONFIG_DEBUG_FS :             2602 seconds.
With CONFIG_DEBUG_FS:                 2640 seconds.
With non-cpu-local atomic statistics: 14569 seconds.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-12-17 01:57:08 +00:00

65 lines
2.0 KiB
C

/*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope 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.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Further private data for which no space exists in mips_fpu_struct.
* This should be subsumed into the mips_fpu_struct structure as
* defined in processor.h as soon as the absurd wired absolute assembler
* offsets become dynamic at compile time.
*
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
*/
#ifndef _ASM_FPU_EMULATOR_H
#define _ASM_FPU_EMULATOR_H
#include <asm/break.h>
#include <asm/inst.h>
#include <asm/local.h>
#ifdef CONFIG_DEBUG_FS
struct mips_fpu_emulator_stats {
local_t emulated;
local_t loads;
local_t stores;
local_t cp1ops;
local_t cp1xops;
local_t errors;
};
DECLARE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
#define MIPS_FPU_EMU_INC_STATS(M) \
cpu_local_wrap(__local_inc(&__get_cpu_var(fpuemustats).M))
#else
#define MIPS_FPU_EMU_INC_STATS(M) do { } while (0)
#endif /* CONFIG_DEBUG_FS */
extern int mips_dsemul(struct pt_regs *regs, mips_instruction ir,
unsigned long cpc);
extern int do_dsemulret(struct pt_regs *xcp);
/*
* Instruction inserted following the badinst to further tag the sequence
*/
#define BD_COOKIE 0x0000bd36 /* tne $0, $0 with baggage */
/*
* Break instruction with special math emu break code set
*/
#define BREAK_MATH (0x0000000d | (BRK_MEMU << 16))
#endif /* _ASM_FPU_EMULATOR_H */