rich7420 commented on PR #11150:
URL: https://github.com/apache/ozone/pull/11150#issuecomment-5461217234
Quick JMH of `writeChunk` reading the length 3x (old) vs 1x (new) on a
cached channel, page-cache hot, JDK 21 / macOS (5 forks x 5, n=25):
```
chunk old new saved
4KB 1.56 us 0.92 us 0.64 us (~41%)
1MB 25.5 us 24.7 us 0.86 us (~3%)
```
The saving is ~2 fstat (~0.6-0.9 us), roughly constant, so it is a
meaningful fraction only for small cached writes (hsync / small keys /
metadata) and is diluted by data movement at larger chunks. No fsync in this
run, and macOS fstat is pricier than Linux, so the fraction is an upper bound.
Standalone JMH, not part of the PR.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
