On 10/10/12 14:26, Viresh Kumar wrote: [...]
I couldn't understand the difference b/w h/w and s/w coordination. What do we mean by them here.
Following patch added related related_cpu stuff:
commit e8628dd06d66f2e3965ec9742029b401d63434f1 Author: Darrick J. Wong djwong@us.ibm.com Date: Fri Apr 18 13:31:12 2008 -0700
[CPUFREQ] expose cpufreq coordination requirements regardless ofcoordination mechanism
Currently, affected_cpus shows which CPUs need to have their frequency coordinated in software. When hardware coordination is in use, the contents of this file appear the same as when no coordination is required. This can lead to some confusion among user-space programs, for example, that do not know that extra coordination is required to force a CPU core to a particular speed to control power consumption. To fix this, create a "related_cpus" attribute that always displays the coordination map regardless of whatever coordination strategy the cpufreq driver uses (sw or hw). If the cpufreq driver does not provide avalue, fall back to policy->cpus.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
Here is my understanding on this patch. This change is closely related to ACPI cpufreq driver(used mostly on Intel cores). This change was introduced to keep track of the related cpus as returned by ACPI firmware along with affected cpus as imposed by SW. I don't understand the exact difference in Intel cores. I believe it's just for tracking and not used much in the driver.
Regards, Sudeep