Re: [PATCH] x86/cpu: use smp_call_function_many() in arch_freq_prepare_all()

[Thomas Gleixner]

On Wed, Mar 30 2022 at 09:51, Eric Dumazet wrote:
> On Wed, Mar 30, 2022 at 8:58 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>> which I hate with a passion because that allows *unpriviledged* user
>> space to inject systemwide IPIs every 10ms just to read these counters
>> which are providing not more than some estimate and are of no value for
>> the only sane use case of /proc/cpuinfo, i.e. #1 above.
>
> You do realize that before my patch, this is already happening ?
>
> My "optimization" simply replace an open loop of individual IPI with
> use of the broadcast IPI capability.
>
> Are you saying we should remove IPI broadcast and use loops
> of IPI, one cpu at a time ?

I rather have no IPIs at all...