Re: [lkp-robot] [Kbuild] 050e9baa9d: netperf.Throughput_total_tps -5.6% regression (FYI)

[Huang\, Ying]

Hi, Linus,

Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:

> On Thu, Jun 21, 2018 at 5:10 PM kernel test robot <xiaolong.ye@xxxxxxxxx> wrote:
>>
>> FYI, we noticed a -5.6% regression of netperf.Throughput_total_tps
>> due to commit 050e9b ("Kbuild: rename CC_STACKPROTECTOR[_STRONG]
>> config variables")
>
> That's perhaps a surprisingly large cost to stack protector, but you
> did move from "no stack protector at all":
>
>> $ grep STACKPROTECTOR config-4.17.0-11782-gbe779f0
>> CONFIG_HAVE_CC_STACKPROTECTOR=y
>> CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
>> # CONFIG_CC_STACKPROTECTOR is not set
>> CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
>
> To having the *strong* stack protector enabled:
>
>> $ grep STACKPROTECTOR config-4.17.0-11783-g050e9baa
>> CONFIG_HAVE_CC_STACKPROTECTOR=y
>> CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
>> CONFIG_STACKPROTECTOR=y
>> CONFIG_STACKPROTECTOR_STRONG=y
>> CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
>
> so you're testing the "no overhead" case to the "worst overhead" case.

Do you have interest in some other comparison?

Best Regards,
Huang, Ying