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author | Janne Grunau <janne-libav@jannau.net> | 2011-12-21 01:18:01 +0100 |
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committer | Janne Grunau <janne-libav@jannau.net> | 2011-12-22 21:50:07 +0100 |
commit | ea4d5f48373ab856e01a3cf05426db6e823e01d1 (patch) | |
tree | 0821c1f58e1ff129e798e959f758ae3f11fff81d /libavcodec | |
parent | f77f640b3035d357a6c6ffcea243c7ea0d8ebc67 (diff) | |
download | ffmpeg-ea4d5f48373ab856e01a3cf05426db6e823e01d1.tar.gz |
linux: use number of CPUs as automatic thread count
Use sched_getaffinity to determine the number of logical CPUs.
Limits the number of threads to 16 since slice threading of H.264
seems to be buggy with more than 16 threads.
Diffstat (limited to 'libavcodec')
-rw-r--r-- | libavcodec/pthread.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/libavcodec/pthread.c b/libavcodec/pthread.c index ac15fefd68..1800f291d7 100644 --- a/libavcodec/pthread.c +++ b/libavcodec/pthread.c @@ -30,6 +30,12 @@ */ #include "config.h" + +#if HAVE_SCHED_GETAFFINITY +#define _GNU_SOURCE +#include <sched.h> +#endif + #include "avcodec.h" #include "internal.h" #include "thread.h" @@ -133,6 +139,29 @@ typedef struct FrameThreadContext { int die; ///< Set when threads should exit. } FrameThreadContext; + +/* H264 slice threading seems to be buggy with more than 16 threads, + * limit the number of threads to 16 for automatic detection */ +#define MAX_AUTO_THREADS 16 + +static int get_logical_cpus(AVCodecContext *avctx) +{ + int ret, nb_cpus = 1; +#if HAVE_SCHED_GETAFFINITY + cpu_set_t cpuset; + + CPU_ZERO(&cpuset); + + ret = sched_getaffinity(0, sizeof(cpuset), &cpuset); + if (!ret) { + nb_cpus = CPU_COUNT(&cpuset); + } +#endif + av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus); + return FFMIN(nb_cpus, MAX_AUTO_THREADS); +} + + static void* attribute_align_arg worker(void *v) { AVCodecContext *avctx = v; @@ -237,6 +266,13 @@ static int thread_init(AVCodecContext *avctx) ThreadContext *c; int thread_count = avctx->thread_count; + if (!thread_count) { + int nb_cpus = get_logical_cpus(avctx); + // use number of cores + 1 as thread count if there is motre than one + if (nb_cpus > 1) + thread_count = avctx->thread_count = nb_cpus + 1; + } + if (thread_count <= 1) { avctx->active_thread_type = 0; return 0; @@ -697,6 +733,13 @@ static int frame_thread_init(AVCodecContext *avctx) FrameThreadContext *fctx; int i, err = 0; + if (!thread_count) { + int nb_cpus = get_logical_cpus(avctx); + // use number of cores + 1 as thread count if there is motre than one + if (nb_cpus > 1) + thread_count = avctx->thread_count = nb_cpus + 1; + } + if (thread_count <= 1) { avctx->active_thread_type = 0; return 0; |