Add upstream fix for excessive alsasink CPU usage

This commit is contained in:
Daniel Drake 2013-01-24 13:25:18 -06:00
parent 35a0f42034
commit 90cbd03f32
2 changed files with 97 additions and 1 deletions

91
alsa-delay-lock.patch Normal file
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@ -0,0 +1,91 @@
From 67a7b5a99317ca1f92fb6a88542647aa3ad92c4b Mon Sep 17 00:00:00 2001
From: yanghuolin <Huolin.Yang@delphi.com>
Date: Thu, 15 Nov 2012 08:31:47 +0000
Subject: alsasink: don't use 100% CPU
The root cause is that alsa-lib is not thread safe for the same handle.
There are two threads in the gstreamer accessing alsa-lib not serilized.
The race condition happens when one thread holds the old framebuffer app_ptr
position in the kernel, another thread advances the framebuffer app_ptr.
when the former thread is scheduled to run again, it overwrites the app_ptr
to old value by copying from kernel.Thus,the app_ptr in the upper
alsa-lib(pcm_rate) become one period size more advanced than the lower
alsa-lib(pcm_hw & kernel).
gstreamer uses noblock and poll method to communicate with the alsa-lib.
The app_ptr unsync situation as described above makes the poll return immediately because
it concludes there is enough space for the ring-buffer via the low-level alsa-lib.
The write function returns immediately because it concludes there is not enough
space for the ring-buffer from the upper-level alsa-lib. Then the loop of poll
and write runs again and again until another period size is available for
ring-buffer.This leads to the cpu 100 problem.
delay_lock is used to avoid the race condition.
Fixes: https://bugzilla.gnome.org/show_bug.cgi?id=690937
---
diff --git a/ext/alsa/gstalsasink.c b/ext/alsa/gstalsasink.c
index 1ef6b91..81731b6 100644
--- a/ext/alsa/gstalsasink.c
+++ b/ext/alsa/gstalsasink.c
@@ -118,6 +118,7 @@ gst_alsasink_finalise (GObject * object)
g_free (sink->device);
g_mutex_clear (&sink->alsa_lock);
+ g_mutex_clear (&sink->delay_lock);
g_mutex_lock (&output_mutex);
--output_ref;
@@ -255,6 +256,7 @@ gst_alsasink_init (GstAlsaSink * alsasink)
alsasink->handle = NULL;
alsasink->cached_caps = NULL;
g_mutex_init (&alsasink->alsa_lock);
+ g_mutex_init (&alsasink->delay_lock);
g_mutex_lock (&output_mutex);
if (output_ref == 0) {
@@ -1011,7 +1013,9 @@ gst_alsasink_write (GstAudioSink * asink, gpointer data, guint length)
if (err < 0) {
GST_DEBUG_OBJECT (asink, "wait error, %d", err);
} else {
+ GST_DELAY_SINK_LOCK (asink);
err = snd_pcm_writei (alsa->handle, ptr, cptr);
+ GST_DELAY_SINK_UNLOCK (asink);
}
GST_DEBUG_OBJECT (asink, "written %d frames out of %d", err, cptr);
@@ -1057,7 +1061,9 @@ gst_alsasink_delay (GstAudioSink * asink)
alsa = GST_ALSA_SINK (asink);
+ GST_DELAY_SINK_LOCK (asink);
res = snd_pcm_delay (alsa->handle, &delay);
+ GST_DELAY_SINK_UNLOCK (asink);
if (G_UNLIKELY (res < 0)) {
/* on errors, report 0 delay */
GST_DEBUG_OBJECT (alsa, "snd_pcm_delay returned %d", res);
diff --git a/ext/alsa/gstalsasink.h b/ext/alsa/gstalsasink.h
index 3a64a92..8c4c1b0 100644
--- a/ext/alsa/gstalsasink.h
+++ b/ext/alsa/gstalsasink.h
@@ -43,6 +43,10 @@ typedef struct _GstAlsaSinkClass GstAlsaSinkClass;
#define GST_ALSA_SINK_LOCK(obj) (g_mutex_lock (GST_ALSA_SINK_GET_LOCK (obj)))
#define GST_ALSA_SINK_UNLOCK(obj) (g_mutex_unlock (GST_ALSA_SINK_GET_LOCK (obj)))
+#define GST_DELAY_SINK_GET_LOCK(obj) (&GST_ALSA_SINK_CAST (obj)->delay_lock)
+#define GST_DELAY_SINK_LOCK(obj) (g_mutex_lock (GST_DELAY_SINK_GET_LOCK (obj)))
+#define GST_DELAY_SINK_UNLOCK(obj) (g_mutex_unlock (GST_DELAY_SINK_GET_LOCK (obj)))
+
/**
* GstAlsaSink:
*
@@ -73,6 +77,7 @@ struct _GstAlsaSink {
GstCaps *cached_caps;
GMutex alsa_lock;
+ GMutex delay_lock;
};
struct _GstAlsaSinkClass {
--
cgit v0.9.0.2-2-gbebe

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@ -2,13 +2,14 @@
Name: gstreamer1-plugins-base Name: gstreamer1-plugins-base
Version: 1.0.5 Version: 1.0.5
Release: 2%{?dist} Release: 3%{?dist}
Summary: GStreamer streaming media framework base plugins Summary: GStreamer streaming media framework base plugins
License: LGPLv2+ License: LGPLv2+
URL: http://gstreamer.freedesktop.org/ URL: http://gstreamer.freedesktop.org/
Source0: http://gstreamer.freedesktop.org/src/gst-plugins-base/gst-plugins-base-%{version}.tar.xz Source0: http://gstreamer.freedesktop.org/src/gst-plugins-base/gst-plugins-base-%{version}.tar.xz
Patch0: 0001-missing-plugins-Remove-the-mpegaudioversion-field.patch Patch0: 0001-missing-plugins-Remove-the-mpegaudioversion-field.patch
Patch1: alsa-delay-lock.patch
BuildRequires: gstreamer1-devel >= %{version} BuildRequires: gstreamer1-devel >= %{version}
BuildRequires: gobject-introspection-devel >= 1.31.1 BuildRequires: gobject-introspection-devel >= 1.31.1
@ -89,6 +90,7 @@ for the GStreamer Base Plugins library.
%prep %prep
%setup -q -n gst-plugins-base-%{version} %setup -q -n gst-plugins-base-%{version}
%patch0 -p1 %patch0 -p1
%patch1 -p1
%build %build
@ -333,6 +335,9 @@ chrpath --delete $RPM_BUILD_ROOT%{_bindir}/gst-discoverer-1.0
%changelog %changelog
* Thu Jan 24 2013 Daniel Drake <dsd@laptop.org> - 1.0.5-3
- Add upstream fix for excessive alsasink CPU usage
* Fri Jan 18 2013 Brian Pepple <bpepple@fedoraproject.org> - 1.0.5-2 * Fri Jan 18 2013 Brian Pepple <bpepple@fedoraproject.org> - 1.0.5-2
- Add patch to fix missing mp3 codec discovery. (#680809, #896018) - Add patch to fix missing mp3 codec discovery. (#680809, #896018)