René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Add runtime control for `profiling.sampling`","articleBody":"# Feature or enhancement\n\n### Proposal:\n\nThe idea is to add an optional control channel (socket? named pipe?), so another process can start, stop etc. profiling without killing/restarting the profiler completely. Right now, the only option is to interact with it via TUI mode or just stop it via Ctrl-C.\n\nWhile working on https://github.com/psf/pyperf/pull/230 I ran into the following problem: some parts (eg: warming up) of benchmarking should not be profiled, as they do not add any value. My only option was sending [SIGINT signal](https://github.com/psf/pyperf/pull/230/changes#diff-28457f773c4dfe0a6128b86f6489077926b7abe4707da7985e01c0981d50ce3aR237).\n\nGenerally, the current flow is nice for headful sessions but it could be improved for (especially long-running) headless sessions.\n\n[perf record --control](https://man7.org/linux/man-pages/man1/perf-record.1.html) does it in a similar way:\n\n```\n       --control=fifo:ctl-fifo[,ack-fifo], --control=fd:ctl-fd[,ack-fd]\n           ctl-fifo / ack-fifo are opened and used as ctl-fd / ack-fd as\n           follows. Listen on ctl-fd descriptor for command to control\n           measurement.\n\n       Available commands:\n\n       •   enable : enable events\n       •   disable : disable events\n       •   enable name : enable event name\n       •   disable name : disable event name\n       •   snapshot : AUX area tracing snapshot).\n       •   stop : stop perf record\n       •   ping : ping\n       •   'evlist [-v|-g|-F] : display all events\n               -F  Show just the sample frequency used for each event.\n               -v  Show all fields.\n               -g  Show event group information.\n```\n\nSpecifically:\n\n- We could start with just `enable` and `disable` initially. `snapshot` next but it'd be lovely to dump without loosing accumulated data. Or maybe even `set_rate`.\n- Possible transport layers could be Unix sockets (works great on Linux) or named pipe. One option might be portable, another not?\n- Possble new arguments like `--control unix:/tmp/tachyon-ctl.sock` or `--control fifo:/tmp/tachyon-ctl`, similar to what [perf record --control](https://man7.org/linux/man-pages/man1/perf-record.1.html) does.\n\nIt could be also ommited from the documentation initially, so we don't limit ourselves too early.\n\n### Has this already been discussed elsewhere?\n\nNo response given\n\n### Links to previous discussion of this feature:\n\n_No response_\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-149958\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/maurycy","@type":"Person","name":"maurycy"},"datePublished":"2026-03-02T09:51:16.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/145411/cpython/issues/145411"}