Bug 96274 – YouTube’s start page is very slow

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKitGTK

[Paul Menzel]

Using Debian Sid/unstable with libwebkitgtk 1.8.1-3.1, YouTube’s start page is really slow for some month now. Accessing the URL location bar or scrolling takes several seconds. All other YouTube pages work fine. So I guess YouTube changed something on their start page causing this. Maybe this is JavaScript related?

I confirmed this issue with GtkLauncher and Midori built from Git.

    commit fefc3b2cbe463815a554ea8490390ba46177d056
    Author: Christian Dywan <[e-mail]>
    Date:   Sun Sep 9 21:50:31 2012 +0200

        Merge build_thumbnail_path into Midori.SpeedDial

Please advise me how to track that issue down.

[Paul Menzel]

$ glxinfo|grep -iE "render(er|ing)"
direct rendering: Yes
OpenGL renderer string: Gallium 0.4 on AMD RS780

[Paul Menzel]

kov in #webkit on irc.freenode.net is not able to reproduce it with Epiphany and GtkLauncher. He uses an Intel graphics chip with the Intel driver so it might be a driver problem.

[Paul Menzel]

By the way, when YouTube’s start page is loaded, top does not show a high CPU usage. Xorg is shown to use 20 %. I do not know if that is an indication for anything though.

[Paul Menzel]

I hate that. After running GtkLauncher under perf_3.2 everything worked fine.

$ perf report
  2,86%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderBox::mapLocalToContainer(WebCore::RenderBoxModelObject*, bool,
  2,63%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderBox::computeRectForRepaint(WebCore::RenderBoxModelObject*, Web
  2,14%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderObject::containingBlock() const

Then trying Midori again everything worked too. So now I cannot reproduce it again. I am going to try that after a restart again and report back.

[Paul Menzel]

I can reproduce it again after restarting the system. I am not sure how to debug this. Help is very much appreciated.

# cmdline : /usr/bin/perf_3.2 record /usr/lib/webkitgtk-3.0-0/libexec/GtkLauncher 
# event : name = cycles, type = 0, config = 0x0, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_kern = 0, id = { 79, 80 }
# HEADER_CPU_TOPOLOGY info available, use -I to display
# ========
#
# Events: 6K cycles
#
# Overhead      Command                       Shared Object                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Symbol
# ........  ...........  ..................................  ............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
#
     2.09%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderBox::computeRectForRepaint(WebCore::RenderBoxModelObject*, WebCore::IntRect&, bool) const
     1.97%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderBox::mapLocalToContainer(WebCore::RenderBoxModelObject*, bool, bool, WebCore::TransformState&, bool*) const
     1.53%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderLayer::hitTestLayer(WebCore::RenderLayer*, WebCore::RenderLayer*, WebCore::HitTestRequest const&, WebCore::HitTestResult&, WebCore::IntRect const&, WebCore::IntPoint const&, bool, WebCore::HitTestingTransformState const*, double*)
     1.45%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderLayer::convertToLayerCoords(WebCore::RenderLayer const*, WebCore::IntPoint&) const
     1.35%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] __x86.get_pc_thunk.bx
     1.33%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderObject::containingBlock() const
     1.26%  GtkLauncher  [kernel.kallsyms]                   [k] acpi_pm_read
     1.19%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderBox::offsetFromContainer(WebCore::RenderObject*, WebCore::IntPoint const&) const
     1.18%  GtkLauncher  libc-2.13.so                        [.] __memcpy_ia32
     0.98%    gtk-gnash  ld-2.13.so                          [.] do_lookup_x
     0.88%  GtkLauncher  libm-2.13.so                        [.] __lroundf
     0.87%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderLayer::calculateRects(WebCore::RenderLayer const*, WebCore::RenderRegion*, WebCore::IntRect const&, WebCore::IntRect&, WebCore::ClipRect&, WebCore::ClipRect&, WebCore::ClipRect&, bool, WebCore::OverlayScrollbarSizeRelevancy) const
     0.79%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderBox::topLeftLocationOffset() const
     0.78%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::TransformState::move(int, int, WebCore::TransformState::TransformAccumulation)
     0.77%    gtk-gnash  [kernel.kallsyms]                   [k] copy_user_highpage.isra.27
     0.72%  GtkLauncher  ld-2.13.so                          [.] do_lookup_x
     0.68%  GtkLauncher  [kernel.kallsyms]                   [k] get_page_from_freelist
     0.67%  GtkLauncher  libpthread-2.13.so                  [.] pthread_mutex_lock
     0.64%  GtkLauncher  libgobject-2.0.so.0.3200.3          [.] g_type_check_instance_is_a
     0.62%  GtkLauncher  libfreetype.so.6.8.1                [.] 0xb11c  
     0.61%  GtkLauncher  libpixman-1.so.0.26.0               [.] 0x84a07 
     0.60%  GtkLauncher  libfreetype.so.6.8.1                [.] TT_RunIns
     0.56%  GtkLauncher  libjpeg.so.8.4.0                    [.] ycc_rgb_convert
     0.56%  GtkLauncher  libc-2.13.so                        [.] __strcmp_ia32
     0.55%  GtkLauncher  libwebkitgtk-3.0.so.0.13.2          [.] WebCore::RenderObject::container(WebCore::RenderBoxModelObject*, bool*) const
     0.52%  GtkLauncher  libc-2.13.so                        [.] _int_malloc
[…]

[Martin Robinson]

Is it possible for you to confirm that this is still an issue in the 1.10.x series?

[Paul Menzel]

I am unable to reproduce it in one try in Debian Sid/unstable with Midori 0.5.11 (0.5.11-ds1-4+b1) and WebKitGTK+ 2.4.11 (2.4.11-3). So I change the status to RESOLVED/FIXED.