From: Thomas Gleixner <tglx@linutronix.de>
To: Eric Dumazet <edumazet@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
the arch/x86 maintainers <x86@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] x86/cpu: use smp_call_function_many() in arch_freq_prepare_all()
Date: Wed, 30 Mar 2022 19:02:36 +0200 [thread overview]
Message-ID: <87bkxnnzkj.ffs@tglx> (raw)
In-Reply-To: <CANn89i+aCnUQj+UkRQBQ+mkL3xeFCmSkgeCYx+hmMNmko+EZ4Q@mail.gmail.com>
On Wed, Mar 30 2022 at 09:51, Eric Dumazet wrote:
> On Wed, Mar 30, 2022 at 8:58 AM Thomas Gleixner <tglx@linutronix.de> 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...
next prev parent reply other threads:[~2022-03-30 17:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-11 1:17 [PATCH] x86/cpu: use smp_call_function_many() in arch_freq_prepare_all() Eric Dumazet
2022-03-11 16:31 ` Paul E. McKenney
2022-03-11 16:35 ` Rafael J. Wysocki
2022-03-23 16:05 ` Eric Dumazet
2022-03-30 15:58 ` Thomas Gleixner
2022-03-30 16:51 ` Eric Dumazet
2022-03-30 17:02 ` Thomas Gleixner [this message]
2022-03-30 17:05 ` Eric Dumazet
2022-03-30 17:16 ` Eric Dumazet
2022-03-30 18:10 ` Thomas Gleixner
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