Graphs for ExpectedQueueingTime, such as https://uma.googleplex.com/p/chrome/histograms/?endDate=20171205&dayCount=1&histograms=RendererScheduler.ExpectedQueueingTimeByFrameType.MainFrameBackground%2CRendererScheduler.ExpectedTaskQueueingDuration&fixupData=true&showMax=true&filters=channel%2Ceq%2C1%2Cisofficial%2Ceq%2CTrue&implicitFilters=isofficial show that we need to consider changing the units in which EQT is reported, because the first bucket is highly concentrated on 0-1. If changing the units causes no change, then that means that the concentration is caused by a bunch of pure 0s, but that seems a bit unlikely.
The following revision refers to this bug: https://chromium.googlesource.com/chromium/src.git/+/ede1608e6ad59da35f7174779f539081d89bbbbf commit ede1608e6ad59da35f7174779f539081d89bbbbf Author: Nicolas Pena <npm@chromium.org> Date: Thu Dec 07 23:09:41 2017 Report ExpectedQueueingTime in microseconds part 1 This CL adds the UMA RendererScheduler.ExpectedTaskQueueingDuration2 to record Expected Queueing Time in microseconds. It also adds the UMA RendererScheduler.ExpectedQueueingTimeByFrameStatus.MainFrameBackground, which is the microsecond-analogue of the UMA metric RendererScheduler.ExpectedQueueingTimeByFrameType.MainFrameBackground. Only one is added to first check whether the resolution change fixes the problem of the first bucket concentrating too high percentiles for split Expected Queueing Time UMA histograms. Also, FrameStatus is used instead of FrameType due to recent code renaming of the types used. If the test goes well, a followup CL will add the other microsecond UMA metrics. The millisecond metrics could be deprecated in the future, but ample warning is required, especially for the widely used metric RendererScheduler.ExpectedTaskQueueingDuration. Bug: 792965 Change-Id: If3d45506a43af21121d7116715d23fc97b5f6f74 Reviewed-on: https://chromium-review.googlesource.com/809566 Commit-Queue: Nicolás Peña Moreno <npm@chromium.org> Reviewed-by: Ilya Sherman <isherman@chromium.org> Reviewed-by: Alexander Timin <altimin@chromium.org> Reviewed-by: Timothy Dresser <tdresser@chromium.org> Cr-Commit-Position: refs/heads/master@{#522598} [modify] https://crrev.com/ede1608e6ad59da35f7174779f539081d89bbbbf/third_party/WebKit/Source/platform/scheduler/renderer/queueing_time_estimator.cc [modify] https://crrev.com/ede1608e6ad59da35f7174779f539081d89bbbbf/third_party/WebKit/Source/platform/scheduler/renderer/queueing_time_estimator.h [modify] https://crrev.com/ede1608e6ad59da35f7174779f539081d89bbbbf/third_party/WebKit/Source/platform/scheduler/renderer/queueing_time_estimator_unittest.cc [modify] https://crrev.com/ede1608e6ad59da35f7174779f539081d89bbbbf/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc [modify] https://crrev.com/ede1608e6ad59da35f7174779f539081d89bbbbf/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h [modify] https://crrev.com/ede1608e6ad59da35f7174779f539081d89bbbbf/tools/metrics/histograms/histograms.xml
The following revision refers to this bug: https://chromium.googlesource.com/chromium/src.git/+/5dc0ba639304f510a0c23f6c6a5e730e80239f9a commit 5dc0ba639304f510a0c23f6c6a5e730e80239f9a Author: Nicolas Pena <npm@chromium.org> Date: Tue Dec 12 18:20:02 2017 Report ExpectedQueueingTime in microseconds part 2 This CL adds UMA histograms for reporting split Expected Queueing Time in microseconds, making obsolete the histograms of splits in ms. The total, RendererScheduler.ExpectedTaskQueueingDuration, is left untouched because it is more widely used. The preliminary data shows that the buckets for the microsecond versions are better. Bug: 792965 Change-Id: I0fe2f62e3c2ad59737d56ab71e6ec7838ddf327d Reviewed-on: https://chromium-review.googlesource.com/820691 Commit-Queue: Nicolás Peña Moreno <npm@chromium.org> Reviewed-by: Ilya Sherman <isherman@chromium.org> Reviewed-by: Alexander Timin <altimin@chromium.org> Cr-Commit-Position: refs/heads/master@{#523479} [modify] https://crrev.com/5dc0ba639304f510a0c23f6c6a5e730e80239f9a/third_party/WebKit/Source/platform/scheduler/renderer/queueing_time_estimator.cc [modify] https://crrev.com/5dc0ba639304f510a0c23f6c6a5e730e80239f9a/third_party/WebKit/Source/platform/scheduler/renderer/queueing_time_estimator.h [modify] https://crrev.com/5dc0ba639304f510a0c23f6c6a5e730e80239f9a/third_party/WebKit/Source/platform/scheduler/renderer/queueing_time_estimator_unittest.cc [modify] https://crrev.com/5dc0ba639304f510a0c23f6c6a5e730e80239f9a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc [modify] https://crrev.com/5dc0ba639304f510a0c23f6c6a5e730e80239f9a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h [modify] https://crrev.com/5dc0ba639304f510a0c23f6c6a5e730e80239f9a/tools/metrics/histograms/histograms.xml
Comment 1 by bugdroid1@chromium.org
, Dec 7 2017