René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Split \"Percentage\" in tachyon flamegraph tooltip UI to \"Percentage of Root\" and \"Percentage of Selected\"","articleBody":"# Feature or enhancement\n\n### Proposal:\n\nFalls under https://github.com/python/cpython/issues/142927\n\nWhen running profiling to identify bottlenecks, I rarely care about global percentage of runtime. For example, the profiling results in https://github.com/matplotlib/matplotlib/pull/31059 show that ~40% of test script runtime is dedicated to imports and module initialization, but I only care about the post-init functions. For that it's more useful to be able to drill down to different top level functions, and measure child percentages relative to that.\n\nSo, I would proposed renaming \"Percentage\" in the tachyon flamegraph tooltips to \"Percentage of Root\", and add a \"Percentage of Selected\" when the user has clicked in to a specific function.\n\nUI mockup for Flamegraph and Inverted Flamegraph, using the demo from here: https://docs.python.org/3.15/_static/tachyon-example-flamegraph.html:\n\n\u003cimg width=\"1302\" height=\"1142\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/2eb2b78c-9890-4077-b286-727912b8b5fc\" /\u003e\n\n\u003cimg width=\"1307\" height=\"587\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/58dd3dc7-607b-4619-83be-05557639a7e3\" /\u003e\n\nWhen at the root, the extra field can be dropped:\n\n\u003cimg width=\"1306\" height=\"645\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/3f62993f-248a-44ad-a1bc-5445358574be\" /\u003e\n\n### Has this already been discussed elsewhere?\n\nThis is a minor feature, which does not need previous discussion elsewhere\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-150266\n* gh-150312\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/scottshambaugh","@type":"Person","name":"scottshambaugh"},"datePublished":"2026-05-22T16:48:29.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/150258/cpython/issues/150258"}