Thanks, Noam. LGTM1.
On Monday, March 9, 2026 at 12:03:32 PM UTC-7 Noam Rosenthal wrote: > > > On Mon, Mar 9, 2026, 6:53 PM Alex Russell <[email protected]> > wrote: > >> I would hope that all forced layouts that generate long jank >> (`getComptuedStyle()` in Noam's example) would generate these events. Is >> there reason to believe they would/should not? > > > They all do, but there is no distinction between time spent in style vs > layout computation. This is a problem of missing attribution, the time > spent in "style and layout" seems like a big opaque purple box that > developers cannot influence or understand. > > >> Best, >> >> Alex >> >> On Monday, March 9, 2026 at 5:30:17 AM UTC-7 Noam Rosenthal wrote: >> >>> On Mon, Mar 9, 2026 at 3:37 AM Yoav Weiss (@Shopify) >>> <[email protected]> wrote: >>> > >>> > >>> > >>> > On Friday, March 6, 2026 at 6:42:41 PM UTC+1 Ian Kilpatrick wrote: >>> > >>> > >>> > >>> > On Fri, Mar 6, 2026 at 9:38 AM Ian Kilpatrick < >>> [email protected]> wrote: >>> > >>> > Hmm... this is pretty fragile, e.g. you are missing the interleaving >>> that occurs for anchor-positioning for example. >>> > >>> https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/css/style_engine.cc;l=3896;drc=4ae3a738cbcbfb87d2bf747e530650484e448361;bpv=1;bpt=1 >>> >>> > >>> > >>> > Fair. Does that mean that these style and layout calcs are not >>> accounted for in the current probes? are they accounted from in the current >>> LoAF implementation? >>> >>> Currently, LoAF cares about two things: >>> - The "lifecycle" style-and-layout timestamp, which is a well defined >>> time within the rendering cycle, regardless of whether more >>> style/layout happens afterwards. >>> - Forced style and layout, as one bucket, when called from a JS method >>> that needs a synchronous result that depends on up to date values. >>> >>> Where I would draw the line between style and layout depends on >>> whether the methods would be called for `getComputedStyle()` or only >>> if a measurement like `offsetLeft` is required. >>> I don't know what the answer for that when anchor position fallbacks are >>> used. >>> >> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/3e80c1b2-6611-42cf-aa24-c3624d0792e0n%40chromium.org.
