
Bisected: The Unfortunate Reason Linux 4.20 Is Running Slower - rsendv
https://www.phoronix.com/scan.php?page=article&item=linux-420-bisect&num=1
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craftyguy
tl;dr: The cause is the Single Thread Indirect Branch Predictors (STIBP) for
cross-hyperthread Spectre mitigation on Intel processors.

I'm not sure why Michael thinks this is a surprise, performance regressions
were practically on the box with these mitigations.

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liamkinne
I don't get the general shock that people have over these mitigations slowing
performance.

Yeah we're throwing out the cash more often, of course it's going to be
slower.

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craftyguy
It gets websites more clicks.

