{
  "$type": "site.standard.document",
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  "path": "/Articles/1067029/",
  "publishedAt": "2026-04-17T13:34:00.000Z",
  "site": "https://lwn.net",
  "tags": [
    "the lazy-preemption mode",
    "this report"
  ],
  "textContent": "One of the more significant changes in the 7.0 kernel release is to use the lazy-preemption mode by default in the CPU scheduler. The scheduler developers have wanted to reduce the number of preemption modes for years, and lazy preemption looks like a step toward that goal. But then there came this report from Salvatore Dipietro that lazy preemption caused a 50% performance regression on a PostgreSQL benchmark. Investigation showed that the situation is not actually so grave, but the episode highlights just how sensitive some workloads can be to configuration changes; there may be surprises in store for other users as well.",
  "title": "[$] The 7.0 scheduler regression that wasn't"
}