WebKitWebProcess idling with constantly 30% of one core after a while
This is with evolution 3.36.1 and webkitgtk 2.28.0.
After using evolution for a bit, the WebKitWebProcess
is constantly using 30% of one CPU core even if evolution is not doing anything. Killing the process fixes it again for a while.
Not sure if this is a webkit or evolution problem, but let's start here.
Backtrace of all threads at some random point in time does not show too much interesting information
Thread 18 (Thread 0x7fa09d9ff700 (LWP 625557)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x7fa044001600, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=2, fds=0x7fa044001600, timeout=<optimized out>, context=0x7fa044000b60) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=0x7fa044000b60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x7fa044001480) at ../../../glib/gmain.c:4241
#4 0x00007fa0b4e1b528 in WTF::RunLoop::run() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#5 0x00007fa0b4dce294 in WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#6 0x00007fa0b4e1ca09 in () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#7 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#8 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 17 (Thread 0x7fa039c62700 (LWP 581582)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fc795e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fc79598, cond=0x55b90fc795c0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fc795c0, mutex=0x55b90fc79598) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 16 (Thread 0x7fa03a463700 (LWP 581581)):
--Type <RET> for more, q to quit, c to continue without paging--
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fc795e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fc79598, cond=0x55b90fc795c0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fc795c0, mutex=0x55b90fc79598) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 15 (Thread 0x7fa03ac64700 (LWP 581580)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fc795e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fc79598, cond=0x55b90fc795c0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fc795c0, mutex=0x55b90fc79598) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 14 (Thread 0x7fa03b465700 (LWP 581579)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fc795e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fc79598, cond=0x55b90fc795c0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fc795c0, mutex=0x55b90fc79598) at pthread_cond_wait.c:638
--Type <RET> for more, q to quit, c to continue without paging--
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 13 (Thread 0x7fa03bc66700 (LWP 581578)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fcad418) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fcad3c8, cond=0x55b90fcad3f0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fcad3f0, mutex=0x55b90fcad3c8) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 12 (Thread 0x7fa054c3a700 (LWP 581577)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fcad418) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fcad3c8, cond=0x55b90fcad3f0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fcad3f0, mutex=0x55b90fcad3c8) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
--Type <RET> for more, q to quit, c to continue without paging--
Thread 11 (Thread 0x7fa05543b700 (LWP 581576)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fcad418) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fcad3c8, cond=0x55b90fcad3f0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fcad3f0, mutex=0x55b90fcad3c8) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 10 (Thread 0x7fa09cebb700 (LWP 581575)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x55b90fcad418) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fcad3c8, cond=0x55b90fcad3f0) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x55b90fcad3f0, mutex=0x55b90fcad3c8) at pthread_cond_wait.c:638
#3 0x00007fa056e0ce6b in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4 0x00007fa056e0ca87 in () at /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#6 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 9 (Thread 0x7fa09e5fc700 (LWP 581570)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x7fa040002ec0, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=2, fds=0x7fa040002ec0, timeout=<optimized out>, context=0x7fa040000b60) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=0x7fa040000b60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>--Type <RET> for more, q to quit, c to continue without paging--
) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x7fa040001d40) at ../../../glib/gmain.c:4241
#4 0x00007fa0b4e1b528 in WTF::RunLoop::run() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#5 0x00007fa0b4dce294 in WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#6 0x00007fa0b4e1ca09 in () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#7 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#8 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 8 (Thread 0x7fa09edfd700 (LWP 581569)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x7fa04c002ec0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7fa04c002ec0, timeout=<optimized out>, context=0x7fa04c000b60) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=0x7fa04c000b60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x7fa04c001d40) at ../../../glib/gmain.c:4241
#4 0x00007fa0b4e1b528 in WTF::RunLoop::run() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#5 0x00007fa0b4dce294 in WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#6 0x00007fa0b4e1ca09 in () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#7 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#8 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 7 (Thread 0x7fa09f5fe700 (LWP 581568)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x7fa048002a90, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7fa048002a90, timeout=<optimized out>, context=0x7fa048000b60) at ../../../glib/gmain.c:4346
--Type <RET> for more, q to quit, c to continue without paging--
#2 g_main_context_iterate (context=0x7fa048000b60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x7fa048001d40) at ../../../glib/gmain.c:4241
#4 0x00007fa0b4e1b528 in WTF::RunLoop::run() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#5 0x00007fa0b4dce294 in WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#6 0x00007fa0b4e1ca09 in () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#7 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#8 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 6 (Thread 0x7fa09fdff700 (LWP 581567)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x7fa0500026a0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7fa0500026a0, timeout=<optimized out>, context=0x7fa050000b60) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=0x7fa050000b60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x7fa050001480) at ../../../glib/gmain.c:4241
#4 0x00007fa0b4e1b528 in WTF::RunLoop::run() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#5 0x00007fa0b4dce294 in WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#6 0x00007fa0b4e1ca09 in () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#7 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#8 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 5 (Thread 0x7fa0ac96c700 (LWP 581566)):
#0 futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa0b515d7cc <bmalloc::StaticPerProcessStorageTraits<bmalloc::Scavenger>::Storage::s_memory+76>) at ../sysdeps/unix/sysv/linux/futex-internal.h:80
--Type <RET> for more, q to quit, c to continue without paging--
#1 __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b90fd1c7b0, cond=0x7fa0b515d7a0 <bmalloc::StaticPerProcessStorageTraits<bmalloc::Scavenger>::Storage::s_memory+32>) at pthread_cond_wait.c:508
#2 __pthread_cond_wait (cond=0x7fa0b515d7a0 <bmalloc::StaticPerProcessStorageTraits<bmalloc::Scavenger>::Storage::s_memory+32>, mutex=0x55b90fd1c7b0) at pthread_cond_wait.c:638
#3 0x00007fa0b26237ac in std::condition_variable::wait(std::unique_lock<std::mutex>&) () at /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4 0x00007fa0b4e2cb92 in bmalloc::Scavenger::threadRunLoop() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#5 0x00007fa0b4e2ce69 in () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#6 0x00007fa0b2628bb0 in () at /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#8 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 4 (Thread 0x7fa0ad388700 (LWP 581558)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x55b90fc70fe0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x55b90fc70fe0, timeout=<optimized out>, context=0x55b90fc71580) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=context@entry=0x55b90fc71580, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a391f in g_main_context_iteration (context=0x55b90fc71580, may_block=1) at ../../../glib/gmain.c:4108
#4 0x00007fa0b97fbd8d in () at /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#5 0x00007fa0b55cc50d in g_thread_proxy (data=0x55b90fc74860) at ../../../glib/gthread.c:807
#6 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#7 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 3 (Thread 0x7fa0adb89700 (LWP 581557)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x7fa0a000f520, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
--Type <RET> for more, q to quit, c to continue without paging--
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=3, fds=0x7fa0a000f520, timeout=<optimized out>, context=0x7fa0a000d5d0) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=0x7fa0a000d5d0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x7fa0a000d6c0) at ../../../glib/gmain.c:4241
#4 0x00007fa0b57efd86 in gdbus_shared_thread_func (user_data=0x7fa0a000d5a0) at ../../../gio/gdbusprivate.c:279
#5 0x00007fa0b55cc50d in g_thread_proxy (data=0x7fa0a0002120) at ../../../glib/gthread.c:807
#6 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#7 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 2 (Thread 0x7fa0aebc8700 (LWP 581553)):
#0 0x00007fa0b6357b4f in __GI___poll (fds=0x55b90fc594f0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fa0b55a37fe in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x55b90fc594f0, timeout=<optimized out>, context=0x55b90fc5ce80) at ../../../glib/gmain.c:4346
#2 g_main_context_iterate (context=context@entry=0x55b90fc5ce80, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4042
#3 0x00007fa0b55a391f in g_main_context_iteration (context=0x55b90fc5ce80, may_block=may_block@entry=1) at ../../../glib/gmain.c:4108
#4 0x00007fa0b55a3971 in glib_worker_main (data=<optimized out>) at ../../../glib/gmain.c:5996
#5 0x00007fa0b55cc50d in g_thread_proxy (data=0x55b90fc22580) at ../../../glib/gthread.c:807
#6 0x00007fa0b23e0f27 in start_thread (arg=<optimized out>) at pthread_create.c:479
#7 0x00007fa0b63622ef in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 1 (Thread 0x7fa0aef0af80 (LWP 581547)):
#0 gdk_frame_clock_get_refresh_info (frame_clock=frame_clock@entry=0x55b910ac9c50 [GdkFrameClockIdle], base_time=base_time@entry=293872285681, refresh_interval_return=refresh_interval_return@entry=0x7ffc9291a6d0, presentation_time_return=presentation_time_return@entry=0x7ffc9291a6c8) at ../../../../gdk/gdkframeclock.c:591
--Type <RET> for more, q to quit, c to continue without paging--
#1 0x00007fa0b5ab3fd3 in compute_min_next_frame_time (last_frame_time=293872285681, clock_idle=0x55b910ac9c50 [GdkFrameClockIdle]) at ../../../../gdk/gdkframeclockidle.c:499
#2 gdk_frame_clock_paint_idle (data=0x55b910ac9c50) at ../../../../gdk/gdkframeclockidle.c:499
#3 0x00007fa0b5a9ed79 in gdk_threads_dispatch (data=0x55b9109404c0, data@entry=<error reading variable: value has been optimized out>) at ../../../../gdk/gdk.c:777
#4 0x00007fa0b55a4054 in g_timeout_dispatch (source=0x55b9120dfcb0, callback=<optimized out>, user_data=<optimized out>) at ../../../glib/gmain.c:4800
#5 0x00007fa0b55a34de in g_main_dispatch (context=0x55b90fc63920) at ../../../glib/gmain.c:3309
#6 g_main_context_dispatch (context=context@entry=0x55b90fc63920) at ../../../glib/gmain.c:3974
#7 0x00007fa0b55a3890 in g_main_context_iterate (context=0x55b90fc63920, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4047
#8 0x00007fa0b55a3b63 in g_main_loop_run (loop=0x55b90ff18fd0) at ../../../glib/gmain.c:4241
#9 0x00007fa0b4e1b528 in WTF::RunLoop::run() () at /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.0.so.18
#10 0x00007fa0b71f8cff in WebKit::AuxiliaryProcessMain<WebKit::WebProcess, WebKit::WebProcessMainGtk>(int, char**) () at ../Source/WebKit/Shared/AuxiliaryProcessMain.h:68
#11 0x00007fa0b628be0b in __libc_start_main (main=0x55b90f956760 <main()>, argc=3, argv=0x7ffc9291a9d8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffc9291a9c8) at ../csu/libc-start.c:308
#12 0x000055b90f9567ea in _start ()
Running in perf top
shows the following at the top
10,13% libgdk-3.so.0.2404.10 [.] gdk_frame_clock_get_refresh_info
6,63% libgdk-3.so.0.2404.10 [.] gdk_frame_clock_paint_idle
6,24% libglib-2.0.so.0.6400.1 [.] g_source_ref
5,99% libglib-2.0.so.0.6400.1 [.] g_source_unref_internal
4,51% libgdk-3.so.0.2404.10 [.] gdk_frame_clock_get_timings
4,34% libglib-2.0.so.0.6400.1 [.] g_mutex_lock
4,30% libglib-2.0.so.0.6400.1 [.] g_hash_table_lookup
4,24% libglib-2.0.so.0.6400.1 [.] g_mutex_unlock
4,20% libgobject-2.0.so.0.6400.1 [.] g_type_check_instance_is_a
[...]
So the frame clock stuff happening on the main thread is most likely the problem here.