[PATCH V2]lscpu: Read available CPUs max and min frequencies

[PATCH V2]lscpu: Read available CPUs max and min frequencies

[Mamatha Inamdar]

Problem:"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.

This patch will read overall CPU max and min frequencies.

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 |   45 ++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 7da441e..86aa875 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -1255,6 +1255,35 @@ read_configured(struct lscpu_desc *desc, int idx)
 	desc->configured[idx] = path_read_s32(_PATH_SYS_CPU "/cpu%d/configure", num);
 }
 
+/* Read overall maximum frequency of cpu */
+static void
+cpu_max_mhz(struct lscpu_desc *desc, char *max_freq)
+{
+	int i;
+	float cpu_freq = atof(desc->maxmhz[0]);
+	for (i = 1; i < desc->ncpuspos; i++) {
+		if (desc->present && CPU_ISSET(real_cpu_num(desc, i), desc->present))
+			if(atof(desc->maxmhz[i]) > cpu_freq)
+				cpu_freq = atof(desc->maxmhz[i]);
+	}
+	sprintf(max_freq, "%.4f", cpu_freq);
+}
+
+/* Read overall minimum frequency of cpu */
+static void
+cpu_min_mhz(struct lscpu_desc *desc, char *min_freq)
+{
+        int i;
+        float cpu_freq = atof(desc->minmhz[0]);
+        for (i = 1; i < desc->ncpuspos; i++) {
+                if (desc->present && CPU_ISSET(real_cpu_num(desc, i), desc->present))
+                        if(atof(desc->minmhz[i]) > cpu_freq)
+                                cpu_freq = atof(desc->minmhz[i]);
+        }
+        sprintf(min_freq, "%.4f", cpu_freq);
+}
+
+
 static void
 read_max_mhz(struct lscpu_desc *desc, int idx)
 {
@@ -1809,7 +1838,9 @@ static void
 print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 {
 	char buf[512];
-	int i;
+	int i = 0;
+	char max_freq[32];
+	char min_freq[32];
 	size_t setsize = CPU_ALLOC_SIZE(maxcpus);
 	struct libscols_table *tb;
 
@@ -1947,10 +1978,14 @@ print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 		add_summary_s(tb, _("CPU dynamic MHz:"), desc->dynamic_mhz);
 	if (desc->static_mhz)
 		add_summary_s(tb, _("CPU static MHz:"), desc->static_mhz);
-	if (desc->maxmhz)
-		add_summary_s(tb, _("CPU max MHz:"), desc->maxmhz[0]);
-	if (desc->minmhz)
-		add_summary_s(tb, _("CPU min MHz:"), desc->minmhz[0]);
+	if (desc->maxmhz){
+		cpu_max_mhz(desc, max_freq);
+		add_summary_s(tb, _("CPU max MHz:"), max_freq);
+	}
+	if (desc->minmhz){
+		cpu_min_mhz(desc, min_freq);
+		add_summary_s(tb, _("CPU min MHz:"), min_freq);
+	}
 	if (desc->bogomips)
 		add_summary_s(tb, _("BogoMIPS:"), desc->bogomips);
 	if (desc->virtflag) {

Re: [PATCH V2]lscpu: Read available CPUs max and min frequencies

[Karel Zak]

On Thu, Apr 27, 2017 at 03:52:59PM +0530, Mamatha Inamdar wrote:
> +/* Read overall maximum frequency of cpu */
> +static void
> +cpu_max_mhz(struct lscpu_desc *desc, char *max_freq)
> +{
> +	int i;
> +	float cpu_freq = atof(desc->maxmhz[0]);
> +	for (i = 1; i < desc->ncpuspos; i++) {
> +		if (desc->present && CPU_ISSET(real_cpu_num(desc, i), desc->present))
> +			if(atof(desc->maxmhz[i]) > cpu_freq)
> +				cpu_freq = atof(desc->maxmhz[i]);
> +	}

 Would be better to use atof() only once?

 if (!desc->present) {
   for (i = 1; i < desc->ncpuspos; i++) {
      if (CPU_ISSET(real_cpu_num(desc, i), desc->present)) {
        float x = atof(desc->maxmhz[i]);
        if (x > cpu_freq)
            cpu_freq = x;
      }
   }
 }

 sprintf(max_freq, "%.4f", cpu_freq);


> +	sprintf(max_freq, "%.4f", cpu_freq);
> +}
> +
> +/* Read overall minimum frequency of cpu */
> +static void
> +cpu_min_mhz(struct lscpu_desc *desc, char *min_freq)
> +{
> +        int i;
> +        float cpu_freq = atof(desc->minmhz[0]);
> +        for (i = 1; i < desc->ncpuspos; i++) {
> +                if (desc->present && CPU_ISSET(real_cpu_num(desc, i), desc->present))
> +                        if(atof(desc->minmhz[i]) > cpu_freq)

  I guess this is typo, should be '<' rather than '>'.

...
     
> +	if (desc->maxmhz){
> +		cpu_max_mhz(desc, max_freq);
> +		add_summary_s(tb, _("CPU max MHz:"), max_freq);
> +	}
> +	if (desc->minmhz){
> +		cpu_min_mhz(desc, min_freq);
> +		add_summary_s(tb, _("CPU min MHz:"), min_freq);
> +	}

 You can share the same buffer and return it by the cpu_max_mhz() and
 cpu_min_mhz(), so the result will be more elegant code:

 char freq_buf[32];
 ...

 if (desc->maxmhz)
    add_summary_s(tb, _("CPU max MHz:"), cpu_max_mhz(desc, freqbuf));
 if (desc->minmhz)
    add_summary_s(tb, _("CPU min MHz:"), cpu_min_mhz(desc, freqbuf));


 :-)

    Karel

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

Re: [PATCH V2]lscpu: Read available CPUs max and min frequencies

[Karel Zak]

On Thu, Apr 27, 2017 at 03:52:59PM +0530, Mamatha Inamdar wrote:
>  sys-utils/lscpu.c |   45 ++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 40 insertions(+), 5 deletions(-)

Applied, thanks with some changes.

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

Re: [PATCH V2]lscpu: Read available CPUs max and min frequencies

[Mamatha Inamdar]

On 05/09/2017 03:54 PM, Karel Zak wrote:
> On Thu, Apr 27, 2017 at 03:52:59PM +0530, Mamatha Inamdar wrote:
>>   sys-utils/lscpu.c |   45 ++++++++++++++++++++++++++++++++++++++++-----
>>   1 file changed, 40 insertions(+), 5 deletions(-)
> Applied, thanks with some changes.

Hi Karel Zak,

I was on vacation, good to know you have made changes and applied the 
patch...
thanks for your support.

Regards
Mamatha Inamdar
>