layout: Disable parallel display list building by default.

I've never see it result in a speedup. Actually, I don't think I've seen
it result in anything better than a 50% slowdown. The arithmetic
intensity is just too low, at least with the current algorithm.

Parallel DL building can still be enabled with a debug flag if the
algorithm is improved.
This commit is contained in:
Patrick Walton 2015-06-12 17:47:50 -07:00
parent 836ac8a0b6
commit eef9c5d9bf
2 changed files with 12 additions and 6 deletions

View file

@ -152,6 +152,9 @@ pub struct Opts {
/// Whether Style Sharing Cache is used
pub disable_share_style_cache: bool,
/// Whether to run absolute position calculation and display list construction in parallel.
pub parallel_display_list_building: bool,
}
fn print_usage(app: &str, opts: &[getopts::OptGroup]) {
@ -183,6 +186,7 @@ pub fn print_debug_usage(app: &str) {
"Display an error when display list geometry escapes overflow region.");
print_option("disable-share-style-cache",
"Disable the style sharing cache.");
print_option("parallel-display-list-building", "Build display lists in parallel.");
println!("");
}
@ -241,6 +245,7 @@ pub fn default_opts() -> Opts {
resources_path: None,
sniff_mime_types: false,
disable_share_style_cache: false,
parallel_display_list_building: false,
}
}
@ -420,6 +425,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
resources_path: opt_match.opt_str("resources-path"),
sniff_mime_types: opt_match.opt_present("sniff-mime-types"),
disable_share_style_cache: debug_options.contains(&"disable-share-style-cache"),
parallel_display_list_building: debug_options.contains(&"parallel-display-list-building"),
};
set(opts);