[PATCH v3 0/6] 32bit ARM branch predictor hardening

On 2018/1/29 22:58, Nishanth Menon wrote:

On Mon, Jan 29, 2018 at 5:36 AM, Hanjun Guo [off-list ref] wrote:
[...]

quoted

By the way, this patch set just enable branch predictor hardening
on arm32 unconditionally, but some of machines (such as wireless
network base station) will not be exposed to user to take advantage
of variant 2, and those machines will be pretty sensitive for
performance, so can we introduce Kconfig or boot option to disable
branch predictor hardening as an option?

I am curious: Have you seen performance degradation with this series?
If yes, is it possible to share the information?

Sorry for the late reply, the performance data for context switch (CFS)
is about 6%~12% drop (A9 based machine) for the first around test, but
the data is not stable, I need to retest then I will update here.

Thanks
Hanjun