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filesrc: remove unused or questionable madvise() calls in deprecated mmap code paths

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use-mmap functionality has been removed in 0.11 and doesn't really
have any performance advantages in most cases anyway. Deprecate
"sequential" property to hint sequential access in mmap mode and
make it non-functional. Chances are no one was using this ever
anyway, or inappropriately.

Remove madvise() calls. We would need to do extensive configure
checks to handle these properly on different systems, and it
doesn't seem worth adding that for code that's already removed
in 0.11 or questionable anyway (like madvise DONTNEED right
before munmap).

https://bugzilla.gnome.org/show_bug.cgi?id=667292
This commit is contained in:
Tim-Philipp Müller 2012-05-15 18:35:58 +01:00
parent 69bd7708c3
commit f85885474c
2 changed files with 7 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
plugins/elements/gstfilesrc.c
View file

@ -173,7 +173,6 @@ enum
#define DEFAULT_MMAPSIZE 4*1024*1024
#define DEFAULT_TOUCH TRUE
#define DEFAULT_USEMMAP FALSE
#define DEFAULT_SEQUENTIAL FALSE
enum
{
@ -288,14 +287,14 @@ gst_file_src_class_init (GstFileSrcClass * klass)
**/
g_object_class_install_property (gobject_class, ARG_USEMMAP,
g_param_spec_boolean ("use-mmap", "Use mmap to read data",
"Whether to use mmap() instead of read()",
"Whether to use mmap() instead of read() (deprecated)",
DEFAULT_USEMMAP, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS |
GST_PARAM_MUTABLE_READY));
g_object_class_install_property (gobject_class, ARG_SEQUENTIAL,
g_param_spec_boolean ("sequential", "Optimise for sequential mmap access",
"Whether to use madvise to hint to the kernel that access to "
"mmap pages will be sequential",
DEFAULT_SEQUENTIAL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS |
"mmap pages will be sequential (deprecated; non-functional)",
FALSE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS |
GST_PARAM_MUTABLE_PLAYING));
gobject_class->finalize = gst_file_src_finalize;
@ -329,7 +328,6 @@ gst_file_src_init (GstFileSrc * src, GstFileSrcClass * g_class)
src->mapbuf = NULL;
src->mapsize = DEFAULT_MMAPSIZE; /* default is 4MB */
src->use_mmap = DEFAULT_USEMMAP;
src->sequential = DEFAULT_SEQUENTIAL;
src->is_regular = FALSE;
@ -418,7 +416,8 @@ gst_file_src_set_property (GObject * object, guint prop_id,
src->touch = g_value_get_boolean (value);
break;
case ARG_SEQUENTIAL:
src->sequential = g_value_get_boolean (value);
GST_WARNING_OBJECT (object, "property \"sequential\" is deprecated and "
"non-functional");
break;
case ARG_USEMMAP:
src->use_mmap = g_value_get_boolean (value);
@ -453,7 +452,7 @@ gst_file_src_get_property (GObject * object, guint prop_id, GValue * value,
g_value_set_boolean (value, src->touch);
break;
case ARG_SEQUENTIAL:
g_value_set_boolean (value, src->sequential);
g_value_set_boolean (value, FALSE);
break;
case ARG_USEMMAP:
g_value_set_boolean (value, src->use_mmap);
@ -538,13 +537,6 @@ gst_mmap_buffer_finalize (GstMmapBuffer * mmap_buffer)
GST_LOG ("freeing mmap()d buffer at %" G_GUINT64_FORMAT "+%u", offset, size);
#ifdef MADV_DONTNEED
/* madvise to tell the kernel what to do with it */
if (madvise (data, size, MADV_DONTNEED) < 0) {
GST_WARNING_OBJECT (src, "warning: madvise failed: %s", g_strerror (errno));
}
#endif
/* now unmap the memory */
if (munmap (data, size) < 0) {
GST_WARNING_OBJECT (src, "warning: munmap failed: %s", g_strerror (errno));
@ -586,16 +578,6 @@ gst_file_src_map_region (GstFileSrc * src, off_t offset, gsize size,
GST_BUFFER_DATA (buf) = mmapregion;
GST_MMAP_BUFFER (buf)->filesrc = src;
#ifdef MADV_SEQUENTIAL
if (src->sequential) {
/* madvise to tell the kernel what to do with it */
if (madvise (mmapregion, size, MADV_SEQUENTIAL) < 0) {
GST_WARNING_OBJECT (src, "warning: madvise failed: %s",
g_strerror (errno));
}
}
#endif
/* fill in the rest of the fields */
GST_BUFFER_SIZE (buf) = size;
GST_BUFFER_OFFSET (buf) = offset;

3
plugins/elements/gstfilesrc.h
View file

@ -64,8 +64,7 @@ struct _GstFileSrc {
gboolean touch; /* whether to touch every page */
gboolean using_mmap; /* whether we opened it with mmap */
gboolean sequential; /* Whether to madvise (MADV_SEQUENTIAL)
for mmap pages */
gboolean seekable; /* whether the file is seekable */
gboolean is_regular; /* whether it's a (symlink to a)
regular file */