[PATCH]lscpu: Read available CPUs max and min frequencies

[PATCH]lscpu: Read available CPUs max and min frequencies

[Mamatha Inamdar]

Problem: On power syatems "lscpu frequency-info" command was always 
reading CPU0 max and min frequencies. If CPU0 is guarded or offline 
then it used to display max and min frequencies as NULL.

Solution: This patch will check for the available/online CPUs
and read the max/min frequencies of that CPU

Test Results:

Before Patch:

#lscpu (CPU0 is guarded/offline)
Architecture:          ppc64le
Byte Order:            Little Endian
CPU(s):                120
On-line CPU(s) list:   8-127
Thread(s) per core:    8
Core(s) per socket:    3
Socket(s):             4
NUMA node(s):          4
Model:                 2.1 (pvr 004b 0201)
Model name:            POWER8E (raw), altivec supported
CPU max MHz:           (null)
CPU min MHz:           (null)
L1d cache:             64K
L1i cache:             32K
L2 cache:              512K
L3 cache:              8192K
NUMA node0 CPU(s):     8-31
NUMA node1 CPU(s):     32-63
NUMA node16 CPU(s):    64-95
NUMA node17 CPU(s):    96-127

With Patch:

# ./lscpu
Architecture:          ppc64le
Byte Order:            Little Endian
CPU(s):                120
On-line CPU(s) list:   8-127
Thread(s) per core:    8
Core(s) per socket:    3
Socket(s):             4
NUMA node(s):          4
Model:                 2.1 (pvr 004b 0201)
Model name:            POWER8E (raw), altivec supported
CPU max MHz:           4322.0000
CPU min MHz:           2061.0000
L1d cache:             64K
L1i cache:             32K
L2 cache:              512K
L3 cache:              8192K
NUMA node0 CPU(s):     8-31
NUMA node1 CPU(s):     32-63
NUMA node16 CPU(s):    64-95
NUMA node17 CPU(s):    96-127

Signed-off-by: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
---
 sys-utils/lscpu.c |   18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 683fd66..7f92b20 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -1775,7 +1775,7 @@ static void
 print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 {
 	char buf[512];
-	int i;
+	int i = 0;
 	size_t setsize = CPU_ALLOC_SIZE(maxcpus);
 
 	print_s(_("Architecture:"), desc->arch);
@@ -1898,9 +1898,21 @@ print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 	if (desc->static_mhz)
 		print_s(_("CPU static MHz:"), desc->static_mhz);
 	if (desc->maxmhz)
-		print_s(_("CPU max MHz:"), desc->maxmhz[0]);
+		for (i = 0; i < desc->ncpuspos; i++) {
+			/*Check for the first online CPU */
+			if (desc->present &&
+				CPU_ISSET(real_cpu_num(desc, i), desc->present))
+				break;
+			}
+	print_s(_("CPU max MHz:"), desc->maxmhz[i]);
 	if (desc->minmhz)
-		print_s(_("CPU min MHz:"), desc->minmhz[0]);
+		for (i = 0; i < desc->ncpuspos; i++) {
+		/*Check for the first online CPU */
+			if (desc->present &&
+				CPU_ISSET(real_cpu_num(desc, i), desc->present))
+				break;
+		}
+	print_s(_("CPU min MHz:"), desc->minmhz[i]);
 	if (desc->bogomips)
 		print_s(_("BogoMIPS:"), desc->bogomips);
 	if (desc->virtflag) {

Re: [PATCH]lscpu: Read available CPUs max and min frequencies

[Rüdiger Meier]

On 04/17/2017 10:30 AM, Mamatha Inamdar wrote:
> Problem: On power syatems "lscpu frequency-info" command was always
> reading CPU0 max and min frequencies. If CPU0 is guarded or offline
> then it used to display max and min frequencies as NULL.
>
> Solution: This patch will check for the available/online CPUs
> and read the max/min frequencies of that CPU

Maybe we could do it even more generically, not letting the first lookup 
win but really using the minimum/maximum over *all* CPUs. Who knows, 
maybe different cores could have different min/max.

cu,
Rudi

Re: [PATCH]lscpu: Read available CPUs max and min frequencies

[Mamatha Inamdar]

Thanks for reviewing,


On 04/17/2017 02:30 PM, Rüdiger Meier wrote:
> On 04/17/2017 10:30 AM, Mamatha Inamdar wrote:
>> Problem: On power syatems "lscpu frequency-info" command was always
>> reading CPU0 max and min frequencies. If CPU0 is guarded or offline
>> then it used to display max and min frequencies as NULL.
>>
>> Solution: This patch will check for the available/online CPUs
>> and read the max/min frequencies of that CPU
>
> Maybe we could do it even more generically, not letting the first 
> lookup win but really using the minimum/maximum over *all* CPUs. Who 
> knows, maybe different cores could have different min/max.

ok..sure..let me check on this.

>
> cu,
> Rudi
>

Re: [PATCH]lscpu: Read available CPUs max and min frequencies

[Karel Zak]

On Mon, Apr 17, 2017 at 11:00:50AM +0200, Rüdiger Meier wrote:
> On 04/17/2017 10:30 AM, Mamatha Inamdar wrote:
> > Problem: On power syatems "lscpu frequency-info" command was always
> > reading CPU0 max and min frequencies. If CPU0 is guarded or offline
> > then it used to display max and min frequencies as NULL.
> > 
> > Solution: This patch will check for the available/online CPUs
> > and read the max/min frequencies of that CPU
> 
> Maybe we could do it even more generically, not letting the first lookup win
> but really using the minimum/maximum over *all* CPUs. Who knows, maybe
> different cores could have different min/max.

Good point.

We already have this information for all CPUs in the desc->maxmhz[]
and desc->minmhz[].  So all we need is function that will return
max/min from the arrays.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: [PATCH]lscpu: Read available CPUs max and min frequencies

[Mamatha Inamdar]

Thanks for your review comments...

On 04/18/2017 04:01 PM, Karel Zak wrote:
> On Mon, Apr 17, 2017 at 11:00:50AM +0200, Rüdiger Meier wrote:
>> On 04/17/2017 10:30 AM, Mamatha Inamdar wrote:
>>> Problem: On power syatems "lscpu frequency-info" command was always
>>> reading CPU0 max and min frequencies. If CPU0 is guarded or offline
>>> then it used to display max and min frequencies as NULL.
>>>
>>> Solution: This patch will check for the available/online CPUs
>>> and read the max/min frequencies of that CPU
>> Maybe we could do it even more generically, not letting the first lookup win
>> but really using the minimum/maximum over *all* CPUs. Who knows, maybe
>> different cores could have different min/max.
> Good point.
>
> We already have this information for all CPUs in the desc->maxmhz[]
> and desc->minmhz[].  So all we need is function that will return
> max/min from the arrays.
>
>      Karel

I have worked on your comments and sent new version of patch, please 
review and let me
know your comments.