diff options
| author | Dan Stoza <stoza@google.com> | 2016-09-12 17:37:52 +0000 |
|---|---|---|
| committer | Android (Google) Code Review <android-gerrit@google.com> | 2016-09-12 17:37:52 +0000 |
| commit | 0c083d43f275382b25ed01baf57c6ee72532e7ea (patch) | |
| tree | 57ee6cdd1b671a177345991120d605449665ed6f | |
| parent | 93ec87d2da0d2c42734492f689cef0bf64e5b66b (diff) | |
| parent | 28ffe198bfab3761f97ce2f74ef479bafc5bbd99 (diff) | |
| download | native-0c083d43f275382b25ed01baf57c6ee72532e7ea.tar.gz | |
Merge "Update default DispSync offsets" into nyc-mr1-dev
| -rw-r--r-- | services/surfaceflinger/Android.mk | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk index dc5e97b324..ffda035a9a 100644 --- a/services/surfaceflinger/Android.mk +++ b/services/surfaceflinger/Android.mk @@ -79,18 +79,36 @@ ifeq ($(TARGET_RUNNING_WITHOUT_SYNC_FRAMEWORK),true) LOCAL_CFLAGS += -DRUNNING_WITHOUT_SYNC_FRAMEWORK endif -# See build/target/board/generic/BoardConfig.mk for a description of this setting. +# The following two BoardConfig variables define (respectively): +# +# - The phase offset between hardware vsync and when apps are woken up by the +# Choreographer callback +# - The phase offset between hardware vsync and when SurfaceFlinger wakes up +# to consume input +# +# Their values can be tuned to trade off between display pipeline latency (both +# overall latency and the lengths of the app --> SF and SF --> display phases) +# and frame delivery jitter (which typically manifests as "jank" or "jerkiness" +# while interacting with the device). The default values should produce a +# relatively low amount of jitter at the expense of roughly two frames of +# app --> display latency, and unless significant testing is performed to avoid +# increased display jitter (both manual investigation using systrace [1] and +# automated testing using dumpsys gfxinfo [2] are recommended), they should not +# be modified. +# +# [1] https://developer.android.com/studio/profile/systrace.html +# [2] https://developer.android.com/training/testing/performance.html + ifneq ($(VSYNC_EVENT_PHASE_OFFSET_NS),) LOCAL_CFLAGS += -DVSYNC_EVENT_PHASE_OFFSET_NS=$(VSYNC_EVENT_PHASE_OFFSET_NS) else - LOCAL_CFLAGS += -DVSYNC_EVENT_PHASE_OFFSET_NS=0 + LOCAL_CFLAGS += -DVSYNC_EVENT_PHASE_OFFSET_NS=1000000 endif -# See build/target/board/generic/BoardConfig.mk for a description of this setting. ifneq ($(SF_VSYNC_EVENT_PHASE_OFFSET_NS),) LOCAL_CFLAGS += -DSF_VSYNC_EVENT_PHASE_OFFSET_NS=$(SF_VSYNC_EVENT_PHASE_OFFSET_NS) else - LOCAL_CFLAGS += -DSF_VSYNC_EVENT_PHASE_OFFSET_NS=0 + LOCAL_CFLAGS += -DSF_VSYNC_EVENT_PHASE_OFFSET_NS=1000000 endif ifneq ($(PRESENT_TIME_OFFSET_FROM_VSYNC_NS),) |