On 4/15/22 03:10, Yu Kuai wrote:Hi,
The single io performance(randwrite):
| bs | 128k | 256k | 512k | 1m | 1280k | 2m | 4m |
| -------- | ---- | ---- | ---- | ---- | ----- | ---- | ---- |
| bw MiB/s | 20.1 | 33.4 | 51.8 | 67.1 | 74.7 | 82.9 | 82.9 |
Although the above data is interesting, it is not sufficient. The above data comes from a setup with a single hard disk. There are many other configurations that are relevant (hard disk array, high speed NVMe, QD=1 USB stick, ...) but for which no conclusions can be drawn from the above data.
Another question is whether the approach of this patch series is the right approach? I would expect that round-robin wakeup of waiters would be ideal from a fairness point of view. However, there are patches in this patch series that guarantee that wakeup of tag waiters won't happen in a round robin fashion.