
Bisected: The Unfortunate Reason Linux 4.20 Is Running Slower - deafcalculus
https://www.phoronix.com/scan.php?page=article&item=linux-420-bisect
======
craftyguy
Dupe:
[https://news.ycombinator.com/item?id=18471448](https://news.ycombinator.com/item?id=18471448)

~~~
jey
also
[https://news.ycombinator.com/item?id=18476562](https://news.ycombinator.com/item?id=18476562)

~~~
sctb
Since that one's the active discussion, we've moved the comments there.

~~~
craftyguy
Your dupe detector is broken. The URLs are the same, how did it not trigger?

~~~
detaro
The second has a different URL, the first probably didn't have enough upvotes
to "arm" the dupe detector?

------
gcb0
to save everyone the click on the dupes:

craftyguy 1 day ago | unvote [-]

tl;dr: The cause is the Single Thread Indirect Branch Predictors (STIBP) for
cross-hyperthread Spectre mitigation on Intel processors.

