<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jul 13, 2020 at 9:15 PM Keith Miller <<a href="mailto:keith_miller@apple.com">keith_miller@apple.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;">If you tell me how to enable paint timing by default, I can start an A/B task for you. I’m probably not qualified to review it for code maturity though.</div></blockquote><div>Awesome, thanks!<br>It's an experimental runtime flag called<span class="gmail-text" style="padding-left:5px;white-space:pre-wrap;color:rgb(0,0,0);font-family:monospace;font-size:medium">PaintTimingEnabled</span><br>I have a patch for enabling it by default here: <a href="https://bugs.webkit.org/show_bug.cgi?id=211736">https://bugs.webkit.org/show_bug.cgi?id=211736</a></div><div>We mainly need to test that measuring paint timing doesn't (badly) influence loading performance.</div><div><br>  </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;"><div><br></div><div>Cheers,</div><div>Keith<br><div><br><blockquote type="cite"><div>On Jul 13, 2020, at 3:02 AM, Noam Rosenthal <<a href="mailto:noam@webkit.org" target="_blank">noam@webkit.org</a>> wrote:</div><br><div><div dir="ltr" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><br><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, May 27, 2020 at 12:04 PM Yoav Weiss <<a href="mailto:yoav@yoav.ws" target="_blank">yoav@yoav.ws</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><a class="gmail_plusreply" id="gmail-m_8650373476589885235gmail-m_2187235869986475176plusReplyChip-0" href="mailto:rniwa@webkit.org" target="_blank">+Ryosuke Niwa</a> <a class="gmail_plusreply" id="gmail-m_8650373476589885235gmail-m_2187235869986475176plusReplyChip-1" href="mailto:achristensen@apple.com" target="_blank">+Alex Christensen</a> who were involved in the spec discussions.<br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, May 27, 2020 at 10:29 AM Noam Rosenthal <<a href="mailto:noam@webkit.org" target="_blank">noam@webkit.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div>Following up on this.</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><div class="gmail_attr">FOn Tue, May 12, 2020 at 10:28 AM Maciej Stachowiak <<a href="mailto:mjs@apple.com" target="_blank">mjs@apple.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br><div><br><blockquote type="cite"><div>On May 11, 2020, at 9:53 PM, Noam Rosenthal <<a href="mailto:noam@webkit.org" target="_blank">noam@webkit.org</a>> wrote:</div><br><div><div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, May 12, 2020 at 1:36 AM Maciej Stachowiak <<a href="mailto:mjs@apple.com" target="_blank">mjs@apple.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><div><br></div>I noticed from comments in one of the Radars that the patch may result in an additional “fake paint”, so it should probably be performance tested. Have you done any testing?<span> </span></div></blockquote><div>I've tested it locally, I haven't noticed any significant side effect, because in complex situations the fake paint only happens once per page and bails early once contentfulness is detected. but I can run any additional test needed.<br> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>We’ll likely want to A/B some of Apple’s page load speed benchmarks.</div></blockquote><div>A/B testing load speed sounds sensible. How do we go about doing that?<br></div></div></div></div></blockquote><br></div><div>Unfortunately our page load speed benchmarks are not public because they incorporate captured page content, which we can’t freely redistribute.</div><div><br></div></blockquote></div></div></blockquote><div>So, can someone else from Apple review that the code is mature enough for this? Simon had reviewed the original patch. Maybe Zalan/Darin? <br><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div></div><div>A helpful person from Apple may be able to set up an A/B test for this patch.<br></div></blockquote></div></div></blockquote><div>What's required to ask for help from a helpful person at Apple? :) </div></div></div></blockquote></div></blockquote><div>Hola<br>Pinging about this again :)<br>The code for paint timing API is sitting there in the repo, waiting either for internal Apple A/B tests, for an additional code maturity review, or for enabling it by default... I'm here if any changes in the code need to be made.<br><br>Trying to figure out how we can proceed with this... <a class="gmail_plusreply" id="gmail-m_8650373476589885235plusReplyChip-1" href="mailto:mjs@apple.com" target="_blank">@Maciej Stachowiak</a>?<br>Cheers</div></div></div><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline">_______________________________________________</span><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;float:none;display:inline">webkit-dev mailing list</span><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><a href="mailto:webkit-dev@lists.webkit.org" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank">webkit-dev@lists.webkit.org</a><br style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><a href="https://lists.webkit.org/mailman/listinfo/webkit-dev" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank">https://lists.webkit.org/mailman/listinfo/webkit-dev</a></div></blockquote></div><br></div></div></blockquote></div></div>