[$] Adding BPF to blk-iocost
The scheduling of block I/O requests has long been a challenge for operating-system kernels.
Why am I seeing this Ranked on source trust — LWN
It ranks mainly on source trust: LWN is the most reliable outlet we track on this subject, and is the only one on the story so far.
Single-sourced. No second organisation has confirmed it yet.
Link-outLink-out, because only one organisation carries it and no first-party source is on it and the subject could not be identified from the text. Link-out means we point at the publisher and say nothing of our own.
| Factor | Weight | Score | Contribution | Where it came from |
|---|---|---|---|---|
| Corroboration | 0.35 | 0.39 | +0.135 38% | 1 independent org on the story. Tier-3 aggregators never corroborate — they can show something is circulating, never that it is true. |
| Source trustleads | 0.25 | 0.85 | +0.212 60% | LWN is the highest-trust source on this story. Trust is taken from the best source, not averaged. |
| Pickup rate | 0.20 | 0.00 | +0.000 0% | One counted organisation, so there is no spread to measure — nothing has picked this up to set a rate. |
| Freshness | 0.20 | 0.02 | +0.004 1% | Halves every 10 hours from the newest item on the story. This is the only factor that rewards a story for nothing more than being recent. |
Corroboration counts distinct organisations, once each, and only from tiers 1 and 2. Freshness halves every 10 hours, so this ranking is a snapshot and will differ at the next build.
Tux.svg: Larry Ewing, Simon Budig, Anja Gerwinski Thomei08 · Public domain · Wikimedia Commons · illustrativeWhat happened
The scheduling of block I/O requests has long been a challenge for operating-system kernels. For many years, the performance characteristics of rotating drives meant that putting considerable resources into request ordering was worthwhile. In a world with fast, solid-state drives, scheduling is more concerned with enforcing fairness between competing users while being fast enough to keep up with drives that can perform millions of I/O operations per second. The blk-iocost I/O controller was designed for the solid-state world and generally performs well, but there is always a desire to do better. This patch series from Tao Cui aims to make blk-iocost more flexible by enabling the loading of a BPF program to make cost decisions.
How this story arrived
Ordered by when each source was first observed, which is what the velocity figure is computed from. Publishers backdate; observed order does not.
- 01 Lwn first seen [$] Adding BPF to blk-iocost
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