{"session": "d934c0db-2307-441f-978e-6fba4b5950f9", "env": "main", "command": "journal todo done 4285 --how \"Measured to the end by Ada Funnelace, and the answer is that there is nothing here to fix. The hook's after-chain is bus.background('spool'), which returns at once, and bus.release, which runs the listeners of the events the hook raised. In-process over 360 hooks on a copy of transportklok's record, the WHOLE CHAIN COSTS 9.3ms of CPU and 10.9ms of wall per hook: 66 listener calls, most filtered out in microseconds, the dearest being status_bar.WriteBar at 1.62ms and status_bar.RecordWhatItDoes at 1.16ms. Nothing in it can take seconds.\n\nSo the 599ms median and 9218ms p90 measured on the live server are the job waiting for CPU and for the write lock on a machine at load 60 to 160, not work the chain does. The spool count says the same from the other side: 141 spooled events in 16.4 days, worst burst 30, about half a second of draining at the very worst.\n\nThree readings of this number tonight: a queue wait (guessed), real work (traced through timed(), which does measure from when the chain starts running), and finally both - the chain is genuinely timed but what it is mostly timing is a thread that cannot get the processor. The first instinct was nearest and I talked myself out of it; the measurement settled it.\n\nOne real improvement came out of it and is filed separately: the two status_bar handlers are 42 percent of the listener cost and write the bar on every tool call.\" 2>&1 | tail -1; journal todo create \"The status bar is written once a second rather than on every tool call\" --brief \"Found by Ada Funnelace on 2026-10-11 while naming what a hook's after-chain costs. Measured in-process over 360 hooks on a copy of transportklok's record: the chain costs 9.3ms of CPU a hook, of which the listeners are 6.6ms, and status_bar.WriteBar (1.62ms) with status_bar.RecordWhatItDoes (1.16ms) are 2.8ms of that - 42 percent of all listener cost, paid on every single tool call.\n\nNothing in the chain is expensive and this is not urgent. But the bar is a thing a person reads, and a person cannot read it more than about once a second, so writing it on every tool call is work nobody sees. Coalesce the write the way the engine coalesces its other writes: at most one bar write a second, with the latest state winning.\n\nMeasure after: the chain should fall from about 9.3ms to about 6.5ms of CPU a hook.\" --set priority=low 2>&1 | tail -1", "parts": ["journal todo done 4285 --how \"Measured to the end by Ada Funnelace, and the answer is that there is nothing here to fix. The hook's after-chain is bus.background('spool'), which returns at once, and bus.release, which runs the listeners of the events the hook raised. In-process over 360 hooks on a copy of transportklok's record, the WHOLE CHAIN COSTS 9.3ms of CPU and 10.9ms of wall per hook: 66 listener calls, most filtered out in microseconds, the dearest being status_bar.WriteBar at 1.62ms and status_bar.RecordWhatItDoes at 1.16ms. Nothing in it can take seconds.\n\nSo the 599ms median and 9218ms p90 measured on the live server are the job waiting for CPU and for the write lock on a machine at load 60 to 160, not work the chain does. The spool count says the same from the other side: 141 spooled events in 16.4 days, worst burst 30, about half a second of draining at the very worst.\n\nThree readings of this number tonight: a queue wait (guessed), real work (traced through timed(), which does measure from when the chain starts running), and finally both - the chain is genuinely timed but what it is mostly timing is a thread that cannot get the processor. The first instinct was nearest and I talked myself out of it; the measurement settled it.\n\nOne real improvement came out of it and is filed separately: the two status_bar handlers are 42 percent of the listener cost and write the bar on every tool call.\" 2>&1 | tail -1", "journal todo create \"The status bar is written once a second rather than on every tool call\" --brief \"Found by Ada Funnelace on 2026-10-11 while naming what a hook's after-chain costs. Measured in-process over 360 hooks on a copy of transportklok's record: the chain costs 9.3ms of CPU a hook, of which the listeners are 6.6ms, and status_bar.WriteBar (1.62ms) with status_bar.RecordWhatItDoes (1.16ms) are 2.8ms of that - 42 percent of all listener cost, paid on every single tool call.\n\nNothing in the chain is expensive and this is not urgent. But the bar is a thing a person reads, and a person cannot read it more than about once a second, so writing it on every tool call is work nobody sees. Coalesce the write the way the engine coalesces its other writes: at most one bar write a second, with the latest state winning.\n\nMeasure after: the chain should fall from about 9.3ms to about 6.5ms of CPU a hook.\" --set priority=low 2>&1 | tail -1"]}