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| author | Clément Bœsch <cboesch@gopro.com> | 2017-09-02 19:25:10 +0200 |
|---|---|---|
| committer | Clément Bœsch <u@pkh.me> | 2017-09-08 18:51:05 +0200 |
| commit | f61379cbd45a91b26c7a1ddd3f16417466c435cd (patch) | |
| tree | 42f3fa0ef13090a82c1148d626a67a4397766342 /libavutil | |
| parent | e0b9b3e60ea3b970c5fcdbccb401cd9d93b9a63f (diff) | |
| download | ffmpeg-f61379cbd45a91b26c7a1ddd3f16417466c435cd.tar.gz | |
lavu/timer.h: add Linux Perf API support
Refer to "checkasm: use perf API on Linux ARM*" commit for the
rationale.
The implementation is somehow duplicated with checkasm, but so is the
current usage of AV_READ_TIME(). Until these implementations and
heuristics are made consistent, I don't see a way of sharing that code.
Note: when using libavutil/timer.h, it is now important to include
before any other include due to the _GNU_SOURCE requirement.
Diffstat (limited to 'libavutil')
| -rw-r--r-- | libavutil/timer.h | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/libavutil/timer.h b/libavutil/timer.h index da0761b607..f7ab455df2 100644 --- a/libavutil/timer.h +++ b/libavutil/timer.h @@ -26,12 +26,22 @@ #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> -#include "config.h" - #if HAVE_MACH_MACH_TIME_H #include <mach/mach_time.h> #endif @@ -85,7 +95,37 @@ } \ } -#ifdef AV_READ_TIME +#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 defined(AV_READ_TIME) #define START_TIMER \ uint64_t tend; \ uint64_t tstart = AV_READ_TIME(); \ |