diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-11-03 16:35:49 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-03 08:50:13 -0700 |
| commit | 941f5f0f6ef5338814145cf2b813cf1f98873e2f (patch) | |
| tree | b5bfebf297b5213cb5ef96af994c5cc84b64e9bb /arch/x86/kernel/cpu/proc.c | |
| parent | 5cb0512c02ecd7e6214e912e4c150f4219ac78e0 (diff) | |
| download | linux-941f5f0f6ef5338814145cf2b813cf1f98873e2f.tar.bz2 | |
x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo
Commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for
/proc/cpuinfo "cpu MHz"") is not sufficient to restore the previous
behavior of "cpu MHz" in /proc/cpuinfo on x86 due to some changes
made after the commit it has reverted.
To address this, make the code in question use arch_freq_get_on_cpu()
which also is used by cpufreq for reporting the current frequency of
CPUs and since that function doesn't really depend on cpufreq in any
way, drop the CONFIG_CPU_FREQ dependency for the object file
containing it.
Also refactor arch_freq_get_on_cpu() somewhat to avoid IPIs and
return cached values right away if it is called very often over a
short time (to prevent user space from triggering IPI storms through
it).
Fixes: 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Cc: stable@kernel.org # 4.13 - together with 890da9cf0983
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/cpu/proc.c')
| -rw-r--r-- | arch/x86/kernel/cpu/proc.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c index 6b7e17bf0b71..4378a729b933 100644 --- a/arch/x86/kernel/cpu/proc.c +++ b/arch/x86/kernel/cpu/proc.c @@ -78,9 +78,11 @@ static int show_cpuinfo(struct seq_file *m, void *v) seq_printf(m, "microcode\t: 0x%x\n", c->microcode); if (cpu_has(c, X86_FEATURE_TSC)) { - unsigned int freq = cpufreq_quick_get(cpu); + unsigned int freq = arch_freq_get_on_cpu(cpu); if (!freq) + freq = cpufreq_quick_get(cpu); + if (!freq) freq = cpu_khz; seq_printf(m, "cpu MHz\t\t: %u.%03u\n", freq / 1000, (freq % 1000)); |