Open
Bug 1408699
Opened 7 years ago
Updated 2 years ago
High keyboard input latency compared to chrome
Categories
(Core :: Graphics, defect, P2)
Tracking
()
NEW
People
(Reporter: gregory.mkv, Unassigned)
References
(Depends on 1 open bug)
Details
(Whiteboard: [gfx-noted])
Attachments
(1 file)
35.03 KB,
image/png
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Details |
User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0 Build ID: 20171014100219 Steps to reproduce: 1. Download https://pavelfatin.com/typometer/ 2. Go to https://www.w3schools.com/TagS/tryit.asp?filename=tryhtml_textarea 3. Measure the input latency of the plain textarea in the right pane Actual results: On every keypress, firefox (32ms avg) has ~3x the latency of Chrome (12ms avg). See screenshot attached with results of comparison. Expected results: Firefox should have better or equal input latency than Chrome. There is perceivable lag when typing into html fields on Firefox that is not acceptable if it is to compete with Chrome performance-wise.
Updated•7 years ago
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Component: Untriaged → Event Handling
Product: Firefox → Core
Comment 1•7 years ago
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(In reply to gregory.mkv from comment #0) > Created attachment 8918593 [details] > Screenshot from 2017-10-14 15-50-50.png > > User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 > Firefox/58.0 > Build ID: 20171014100219 > > Steps to reproduce: > > 1. Download https://pavelfatin.com/typometer/ > 2. Go to https://www.w3schools.com/TagS/tryit.asp?filename=tryhtml_textarea > 3. Measure the input latency of the plain textarea in the right pane > > > > Actual results: > > On every keypress, firefox (32ms avg) has ~3x the latency of Chrome (12ms > avg). > See screenshot attached with results of comparison. > Hello Reporter, Thanks for reporting. To clarify - is the ~3x number applied only to that w3cshools link? What about the data when testing on other websites, for example Facebook or Google search? Also NI Olli & Stone to see if they have comments. > > Expected results: > > Firefox should have better or equal input latency than Chrome. > There is perceivable lag when typing into html fields on Firefox that is not > acceptable if it is to compete with Chrome performance-wise.
Flags: needinfo?(sshih)
Flags: needinfo?(gregory.mkv)
Flags: needinfo?(bugs)
Updated•7 years ago
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Assignee: nobody → sshih
Flags: needinfo?(sshih)
Comment 2•7 years ago
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Hmm, is the latency coming from waiting for vsync. First we get keyboard event in parent, it is sent to child, editor is modified and it causes a layout change, we request vsync from parent/gpu process, get vsync to child and paint and update the layer tree... something like that.
Flags: needinfo?(bugs)
Comment 3•7 years ago
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Yeah I would expect a 2-frame delay between input and visual difference. Both our painting and compositing are vsync-driven.
Reporter | ||
Comment 4•7 years ago
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(In reply to Hsin-Yi Tsai [:hsinyi] from comment #1) > (In reply to gregory.mkv from comment #0) > > Created attachment 8918593 [details] > > Screenshot from 2017-10-14 15-50-50.png > > > > User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 > > Firefox/58.0 > > Build ID: 20171014100219 > > > > Steps to reproduce: > > > > 1. Download https://pavelfatin.com/typometer/ > > 2. Go to https://www.w3schools.com/TagS/tryit.asp?filename=tryhtml_textarea > > 3. Measure the input latency of the plain textarea in the right pane > > > > > > > > Actual results: > > > > On every keypress, firefox (32ms avg) has ~3x the latency of Chrome (12ms > > avg). > > See screenshot attached with results of comparison. > > > > Hello Reporter, Thanks for reporting. To clarify - is the ~3x number applied > only to that w3cshools link? What about the data when testing on other > websites, for example Facebook or Google search? > > Also NI Olli & Stone to see if they have comments. > > > > > Expected results: > > > > Firefox should have better or equal input latency than Chrome. > > There is perceivable lag when typing into html fields on Firefox that is not > > acceptable if it is to compete with Chrome performance-wise. Yes, the ~3x number is the same in every textarea I've tested latency on, incl. other websites. For the purpose of simplicity, I've omitted wysiwyg editors and the like, however.
Flags: needinfo?(gregory.mkv)
Comment 5•7 years ago
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I wonder how this aligns with Hasal's results. Shako, does this surprise you?
Flags: needinfo?(sho)
Priority: -- → P2
I will say the tool surprises me, the tool is awesome and it minimizes the overhead of detecting the screen changes to measure the input latency, this could lead us to think a more efficient way to optimize Hasal. But I'm not surprised about the testing result, I create a new test case testing with the same URL, and the number I have for Firefox is around 33 ms, Chrome is around 17 ms. And the number I had from typometer for Firefox is around 33 ms, but for Chrome is around 23 ms (I think the difference comes from the recording FPS). I think we have the similar result for both browsers on the same URL.
Flags: needinfo?(sho)
Updated•7 years ago
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Assignee: sshih → nobody
Component: Event Handling → Graphics
Updated•6 years ago
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Whiteboard: [gfx-noted]
Comment 7•6 years ago
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May I ask why this is still "unconfirmed" given the response of Shako Ho in comment #6?
Comment 8•6 years ago
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I'll mark it "new" but that's not going to get it fixed any faster.
Status: UNCONFIRMED → NEW
Ever confirmed: true
Updated•2 years ago
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Severity: normal → S3
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Description
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