On 18/03/15 08:27 AM, Pekka Paalanen wrote: > From: Pekka Paalanen <[email protected]> > > This timer delays the output_repaint towards the end of the refresh > period, reducing the time from repaint to present. > > The length of the repaint window can be set in weston.ini. > > The call to weston_output_schedule_repaint_reset() is delayed by one > more period. If we exit the continuous repaint loop (set > output->repaint_scheduled to false) in finish_frame, we may call > start_repaint_loop() unnecessarily. The problem case was actually > observed with two outputs on the DRM backend at 60 Hz, and 7 ms > repaint-window. During a window move, one output was constantly falling > off the continuous repaint loop and introducing additional one frame > latency, leading to jerky window motion. This code now avoids the > problem. > > Changes in v2: > > - Rename repaint_delay_timer to repaint_timer and > output_repaint_delay_handler to output_repaint_timer_handler. > > - When computing the delay, take the current time into account. The timer > uses a relative timeout, so we have to subtract any time already gone. > > Note, that 'gone' may also be negative. DRM has a habit of predicting > the page flip timestamp so it may be still in the future when we get the > completion event. > > - Do also a sanity check 'msec > 1000'. In the unlikely case that > something fails to provide a good timestamp, never delay for more than > one second. > > Signed-off-by: Pekka Paalanen <[email protected]> > --- > man/weston.ini.man | 10 +++++++ > src/compositor.c | 83 > ++++++++++++++++++++++++++++++++++++++++++++++-------- > src/compositor.h | 2 ++ > 3 files changed, 84 insertions(+), 11 deletions(-) > > diff --git a/man/weston.ini.man b/man/weston.ini.man > index 7a353c9..d7df0e4 100644 > --- a/man/weston.ini.man > +++ b/man/weston.ini.man > @@ -137,6 +137,16 @@ directory are: > .fi > .RE > .TP 7 > +.BI "repaint-window=" N > +Set the approximate length of the repaint window in milliseconds. The repaint > +window is used to control and reduce the output latency for clients. If the > +window is longer than the output refresh period, the repaint will be done > +immediately when the previous repaint finishes, not processing client > requests > +in between. If the repaint window is too short, the compositor may miss the > +target vertical blank, increasing output latency. The default value is 7 > +milliseconds. The allowed range is from -10 to 1000 milliseconds. Using a > +negative value will force the compositor to always miss the target vblank. > +.TP 7 > .BI "gbm-format="format > sets the GBM format used for the framebuffer for the GBM backend. Can be > .B xrgb8888, > diff --git a/src/compositor.c b/src/compositor.c > index e060be1..3f6aa7d 100644 > --- a/src/compositor.c > +++ b/src/compositor.c > @@ -62,6 +62,28 @@ > #include "git-version.h" > #include "version.h" > > +#define DEFAULT_REPAINT_WINDOW 7 /* milliseconds */ > + > +#define NSEC_PER_SEC 1000000000 > + > +static void > +timespec_sub(struct timespec *r, > + const struct timespec *a, const struct timespec *b) > +{ > + r->tv_sec = a->tv_sec - b->tv_sec; > + r->tv_nsec = a->tv_nsec - b->tv_nsec; > + if (r->tv_nsec < 0) { > + r->tv_sec--; > + r->tv_nsec += NSEC_PER_SEC; > + } > +} > + > +static int64_t > +timespec_to_nsec(const struct timespec *a) > +{ > + return (int64_t)a->tv_sec * NSEC_PER_SEC + a->tv_nsec; > +} > + > static struct wl_list child_process_list; > static struct weston_compositor *segv_compositor; > > @@ -2346,19 +2368,38 @@ weston_output_schedule_repaint_reset(struct > weston_output *output) > weston_compositor_read_input, compositor); > } > > +static int > +output_repaint_timer_handler(void *data) > +{ > + struct weston_output *output = data; > + struct weston_compositor *compositor = output->compositor; > + > + if (output->repaint_needed && > + compositor->state != WESTON_COMPOSITOR_SLEEPING && > + compositor->state != WESTON_COMPOSITOR_OFFSCREEN && > + weston_output_repaint(output) == 0) > + return 0; > + > + weston_output_schedule_repaint_reset(output); > + > + return 0; > +} > + > WL_EXPORT void > weston_output_finish_frame(struct weston_output *output, > const struct timespec *stamp, > uint32_t presented_flags) > { > struct weston_compositor *compositor = output->compositor; > - int r; > - uint32_t refresh_nsec; > + int32_t refresh_nsec; > + struct timespec now; > + struct timespec gone; > + int msec; > > TL_POINT("core_repaint_finished", TLP_OUTPUT(output), > TLP_VBLANK(stamp), TLP_END); > > - refresh_nsec = 1000000000000UL / output->current_mode->refresh; > + refresh_nsec = 1000000000000LL / output->current_mode->refresh; > weston_presentation_feedback_present_list(&output->feedback_list, > output, refresh_nsec, stamp, > output->msc, > @@ -2366,15 +2407,16 @@ weston_output_finish_frame(struct weston_output > *output, > > output->frame_time = stamp->tv_sec * 1000 + stamp->tv_nsec / 1000000; > > - if (output->repaint_needed && > - compositor->state != WESTON_COMPOSITOR_SLEEPING && > - compositor->state != WESTON_COMPOSITOR_OFFSCREEN) { > - r = weston_output_repaint(output); > - if (!r) > - return; > - } > + weston_compositor_read_presentation_clock(compositor, &now); > + timespec_sub(&gone, &now, stamp); > + msec = (refresh_nsec - timespec_to_nsec(&gone)) / 1000000; /* floor */ > + msec -= compositor->repaint_msec; > > - weston_output_schedule_repaint_reset(output); > + /* Also sanity check. */ > + if (msec < 1 || msec > 1000)
What's the msec > 1000 for? When doing fake presentation clock later I think this will be a problem. I guess at that point I can make the "too long" test conditional on test mode being off... Under normal circumstances maybe we should log (perhaps just the first time) the > 1000 case, as it seems to indicate something is rather wrong? This all looks pretty good to me though, Reviewed-By: Derek Foreman <[email protected]> > + output_repaint_timer_handler(output); > + else > + wl_event_source_timer_update(output->repaint_timer, msec); > } > > static void > @@ -3873,6 +3915,8 @@ weston_output_destroy(struct weston_output *output) > > output->destroying = 1; > > + wl_event_source_remove(output->repaint_timer); > + > weston_presentation_feedback_discard_list(&output->feedback_list); > > weston_compositor_remove_output(output->compositor, output); > @@ -4033,6 +4077,8 @@ weston_output_init(struct weston_output *output, struct > weston_compositor *c, > int x, int y, int mm_width, int mm_height, uint32_t > transform, > int32_t scale) > { > + struct wl_event_loop *loop; > + > output->compositor = c; > output->x = x; > output->y = y; > @@ -4053,6 +4099,10 @@ weston_output_init(struct weston_output *output, > struct weston_compositor *c, > wl_list_init(&output->resource_list); > wl_list_init(&output->feedback_list); > > + loop = wl_display_get_event_loop(c->wl_display); > + output->repaint_timer = wl_event_loop_add_timer(loop, > + output_repaint_timer_handler, output); > + > output->id = ffs(~output->compositor->output_id_pool) - 1; > output->compositor->output_id_pool |= 1 << output->id; > > @@ -4517,6 +4567,17 @@ weston_compositor_init(struct weston_compositor *ec, > weston_compositor_add_debug_binding(ec, KEY_T, > timeline_key_binding_handler, ec); > > + s = weston_config_get_section(ec->config, "core", NULL, NULL); > + weston_config_section_get_int(s, "repaint-window", &ec->repaint_msec, > + DEFAULT_REPAINT_WINDOW); > + if (ec->repaint_msec < -10 || ec->repaint_msec > 1000) { > + weston_log("Invalid repaint_window value in config: %d\n", > + ec->repaint_msec); > + ec->repaint_msec = DEFAULT_REPAINT_WINDOW; > + } > + weston_log("Output repaint window is %d ms maximum.\n", > + ec->repaint_msec); > + > weston_compositor_schedule_repaint(ec); > > return 0; > diff --git a/src/compositor.h b/src/compositor.h > index 2e6ef9d..a451ba3 100644 > --- a/src/compositor.h > +++ b/src/compositor.h > @@ -196,6 +196,7 @@ struct weston_output { > pixman_region32_t previous_damage; > int repaint_needed; > int repaint_scheduled; > + struct wl_event_source *repaint_timer; > struct weston_output_zoom zoom; > int dirty; > struct wl_signal frame_signal; > @@ -683,6 +684,7 @@ struct weston_compositor { > int32_t kb_repeat_delay; > > clockid_t presentation_clock; > + int32_t repaint_msec; > > int exit_code; > }; > _______________________________________________ wayland-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/wayland-devel
