Revert "x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo"
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 10 Nov 2017 19:19:11 +0000 (11:19 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 10 Nov 2017 19:19:11 +0000 (11:19 -0800)
commitea0ee33988778fb73e4f45e7c73fb735787e2f32
tree45ebd3e4347a879157dab48b2bc88f9bf2cf9286
parent3e81277a6edd6b568c3a091a372dfe6368697b21
Revert "x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo"

This reverts commit 941f5f0f6ef5338814145cf2b813cf1f98873e2f.

Sadly, it turns out that we really can't just do the cross-CPU IPI to
all CPU's to get their proper frequencies, because it's much too
expensive on systems with lots of cores.

So we'll have to revert this for now, and revisit it using a smarter
model (probably doing one system-wide IPI at open time, and doing all
the frequency calculations in parallel).

Reported-by: WANG Chao <chao.wang@ucloud.cn>
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Rafael J Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/x86/kernel/cpu/Makefile
arch/x86/kernel/cpu/aperfmperf.c
arch/x86/kernel/cpu/proc.c