1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-12 19:18:44 +02:00
FFmpeg/libavutil/timer.h
Rémi Denis-Courmont d808070547 lavu/riscv: AV_READ_TIME cycle counter
This uses the architected RISC-V 64-bit cycle counter from the
RISC-V unprivileged instruction set.

In 64-bit and 128-bit, this is a straightforward CSR read.
In 32-bit mode, the 64-bit value is exposed as two CSRs, which
cannot be read atomically, so a loop is necessary to detect and fix up
the race condition where the bottom half wraps exactly between the two
reads.
2022-09-13 16:50:43 -03:00

157 lines
6.3 KiB
C

/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* high precision timer, useful to profile code
*/
#ifndef AVUTIL_TIMER_H
#define AVUTIL_TIMER_H
#include "config.h"
#if CONFIG_LINUX_PERF
# ifndef _GNU_SOURCE
# define _GNU_SOURCE
# endif
# include <unistd.h> // read(3)
# include <sys/ioctl.h>
# include <asm/unistd.h>
# include <linux/perf_event.h>
#endif
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#if CONFIG_MACOS_KPERF
#include "macos_kperf.h"
#elif HAVE_MACH_ABSOLUTE_TIME
#include <mach/mach_time.h>
#endif
#include "common.h"
#include "log.h"
#if ARCH_AARCH64
# include "aarch64/timer.h"
#elif ARCH_ARM
# include "arm/timer.h"
#elif ARCH_PPC
# include "ppc/timer.h"
#elif ARCH_RISCV
# include "riscv/timer.h"
#elif ARCH_X86
# include "x86/timer.h"
#endif
#if !defined(AV_READ_TIME)
# if HAVE_GETHRTIME
# define AV_READ_TIME gethrtime
# elif HAVE_MACH_ABSOLUTE_TIME
# define AV_READ_TIME mach_absolute_time
# endif
#endif
#ifndef FF_TIMER_UNITS
# define FF_TIMER_UNITS "UNITS"
#endif
#define TIMER_REPORT(id, tdiff) \
{ \
static uint64_t tsum = 0; \
static int tcount = 0; \
static int tskip_count = 0; \
static int thistogram[32] = {0}; \
thistogram[av_log2(tdiff)]++; \
if (tcount < 2 || \
(tdiff) < 8 * tsum / tcount || \
(tdiff) < 2000) { \
tsum += (tdiff); \
tcount++; \
} else \
tskip_count++; \
if (((tcount + tskip_count) & (tcount + tskip_count - 1)) == 0) { \
int i; \
av_log(NULL, AV_LOG_ERROR, \
"%7" PRIu64 " " FF_TIMER_UNITS " in %s,%8d runs,%7d skips",\
tsum * 10 / tcount, id, tcount, tskip_count); \
for (i = 0; i < 32; i++) \
av_log(NULL, AV_LOG_VERBOSE, " %2d", av_log2(2*thistogram[i]));\
av_log(NULL, AV_LOG_ERROR, "\n"); \
} \
}
#if CONFIG_LINUX_PERF
#define START_TIMER \
static int linux_perf_fd; \
uint64_t tperf; \
if (!linux_perf_fd) { \
struct perf_event_attr attr = { \
.type = PERF_TYPE_HARDWARE, \
.size = sizeof(struct perf_event_attr), \
.config = PERF_COUNT_HW_CPU_CYCLES, \
.disabled = 1, \
.exclude_kernel = 1, \
.exclude_hv = 1, \
}; \
linux_perf_fd = syscall(__NR_perf_event_open, &attr, \
0, -1, -1, 0); \
} \
if (linux_perf_fd == -1) { \
av_log(NULL, AV_LOG_ERROR, "perf_event_open failed: %s\n", \
av_err2str(AVERROR(errno))); \
} else { \
ioctl(linux_perf_fd, PERF_EVENT_IOC_RESET, 0); \
ioctl(linux_perf_fd, PERF_EVENT_IOC_ENABLE, 0); \
}
#define STOP_TIMER(id) \
ioctl(linux_perf_fd, PERF_EVENT_IOC_DISABLE, 0); \
read(linux_perf_fd, &tperf, sizeof(tperf)); \
TIMER_REPORT(id, tperf)
#elif CONFIG_MACOS_KPERF
#define START_TIMER \
uint64_t tperf; \
ff_kperf_init(); \
tperf = ff_kperf_cycles();
#define STOP_TIMER(id) \
TIMER_REPORT(id, ff_kperf_cycles() - tperf);
#elif defined(AV_READ_TIME)
#define START_TIMER \
uint64_t tend; \
uint64_t tstart = AV_READ_TIME(); \
#define STOP_TIMER(id) \
tend = AV_READ_TIME(); \
TIMER_REPORT(id, tend - tstart)
#else
#define START_TIMER
#define STOP_TIMER(id) { }
#endif
#endif /* AVUTIL_TIMER_H */