[elrepo] Where should I go to find kernel issues?

[Leon Fauster]

Am 16.01.2014 um 19:39 schrieb Akemi Yagi <toracat at elrepo.org>:
> On Thu, Jan 16, 2014 at 9:34 AM, Joshua Kramer <joskra42.list at gmail.com> wrote:
>> So I found out that starting with 3.4 I think, the kernel defaults to using
>> the intel_pstate driver instead of acpi_pstate.  If using the intel_pstate
>> driver causes issues (as it did with me), then add this to the kernel boot
>> parameters:
>> 
>> intel_pstate=disable
>> 
>> After doing this, my copy of the 3.12 kernel now uses the acpi driver, and
>> things work as they should.
>> 
>> Of course, using acpi has its drawbacks.  Depending on processor capability,
>> sometimes a longer-running task at low frequency uses more power than a fast
>> task at a high frequency.  The intel_pstate driver knows about this and
>> accomodates.  The issue is that intel_pstate does not use the same governor
>> options as acpi; with intel_pstate, there are only powersave and
>> performance.
>> 
>> So in this case, the "right" solution for users of EL clones is to go hunt
>> down the configurations for the cpuspeed daemon and modify it to not try to
>> set the scaling_governor to something that is not allowed.
>> 
>> This post has more information:
>> https://bbs.archlinux.org/viewtopic.php?pid=1294415#p1294415
> 
> Thank you for posting a followup with useful information. Just as a
> data point, the kernel in RHEL 7 beta (3.10.0-54.0.1.el7) has the
> following config entries:
> 
> CONFIG_CPU_FREQ=y
> CONFIG_CPU_FREQ_TABLE=y
> CONFIG_CPU_FREQ_GOV_COMMON=y
> CONFIG_CPU_FREQ_STAT=m
> CONFIG_CPU_FREQ_STAT_DETAILS=y
> # CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set
> # CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
> CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
> # CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set
> CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
> CONFIG_CPU_FREQ_GOV_POWERSAVE=y
> CONFIG_CPU_FREQ_GOV_USERSPACE=y
> CONFIG_CPU_FREQ_GOV_ONDEMAND=y
> CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
> CONFIG_X86_PCC_CPUFREQ=m
> CONFIG_X86_ACPI_CPUFREQ=m
> CONFIG_X86_ACPI_CPUFREQ_CPB=y
> 
> versus the kernel in RHEL 6.5 (2.6.32-431.el6)
> 
> CONFIG_CPU_FREQ=y
> CONFIG_CPU_FREQ_TABLE=m
> CONFIG_CPU_FREQ_DEBUG=y
> CONFIG_CPU_FREQ_STAT=m
> CONFIG_CPU_FREQ_STAT_DETAILS=y
> # CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set
> # CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set
> CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE=y
> # CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set
> # CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set
> CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
> CONFIG_CPU_FREQ_GOV_POWERSAVE=m
> CONFIG_CPU_FREQ_GOV_USERSPACE=y
> CONFIG_CPU_FREQ_GOV_ONDEMAND=m
> CONFIG_CPU_FREQ_GOV_CONSERVATIVE=m
> CONFIG_X86_PCC_CPUFREQ=m
> CONFIG_X86_ACPI_CPUFREQ=m



EL7 doesn't ship cpuspeed package, any idea how they handle the 
interaction in the ui respectively which "governors" configuration 
supports such "user" interaction (or which package is taking the 
place of cpuspeed)?

--
LF