Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist
On 02/13/2011 06:08 PM, Minoru Usui wrote: So with rounding up request and truncating reports we are on the safe side in both cases. Matthias I agree with you. In this case we are reporting cpu MHz, so we should truncate it. Eric, what do you think? Truncation works for me. I think these patches have missed the cutoff for 0.8.8, though, so I haven't looked closely at them yet. -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist
Hi, Matthias
Thank you for your help.
On Thu, 10 Feb 2011 19:12:46 +0100
Matthias Bolte matthias.bo...@googlemail.com wrote:
2011/2/10 Minoru Usui u...@mxm.nes.nec.co.jp:
Hi, Eric
On Tue, 1 Feb 2011 10:26:36 +0900
Minoru Usui u...@mxm.nes.nec.co.jp wrote:
Hi, Eric
On Mon, 31 Jan 2011 15:46:39 -0700
Eric Blake ebl...@redhat.com wrote:
On 01/27/2011 02:51 AM, Minoru Usui wrote:
virNodeGetInfo() gets from
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq, first.
Signed-off-by: Minoru Usui u...@mxm.nes.nec.co.jp
I haven't looked closely at this series yet...
+ /*
+ * nodeinfo-mhz should return maximum frequency,
+ * but cpu MHz of /proc/cpuinfo is scaled by power saving
feature.
+ * So it gets cpufreq/cpuinfo_max_freq, if possible.
+ */
+ ret = get_cpu_value(0, cpufreq/cpuinfo_max_freq, true);
+ if (ret 0)
+ return -1;
+ else if (ret != 1) {
+ /* convert unit */
+ cpu_mhz = ret / 1000;
But which units is this converting between, and should it truncate or
round up?
I think it divide by 1000 is collect, because my machine returns below
values.
-
# cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_max_freq
231
231
231
231
231
231
231
231
# grep 'cpu MHz' /proc/cpuinfo
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
-
On the other hand, I don't have clear opinion about truncate or round up.
Present implementation of linuxNodeInfoCPUPopulate() selects truncate,
so I implement to truncate logic.
Are my explanations enough?
If not or I'm misunderstanding something, please let me know.
I think we should round up in case we request something, because then
we get at least what we requested. If we truncate a request we might
get less than we requested, this might result in a bad situation.
Recently we switched from truncation to rounding up for memory and
storage request because of this.
But here we are reporting something. In that case we should truncate,
because if we would round up we could report more than there actually
is, this might result in a bad situation too.
So with rounding up request and truncating reports we are on the safe
side in both cases.
Matthias
I agree with you.
In this case we are reporting cpu MHz, so we should truncate it.
Eric, what do you think?
--
Minoru Usui u...@mxm.nes.nec.co.jp
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Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist
2011/2/10 Minoru Usui u...@mxm.nes.nec.co.jp:
Hi, Eric
On Tue, 1 Feb 2011 10:26:36 +0900
Minoru Usui u...@mxm.nes.nec.co.jp wrote:
Hi, Eric
On Mon, 31 Jan 2011 15:46:39 -0700
Eric Blake ebl...@redhat.com wrote:
On 01/27/2011 02:51 AM, Minoru Usui wrote:
virNodeGetInfo() gets from
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq, first.
Signed-off-by: Minoru Usui u...@mxm.nes.nec.co.jp
I haven't looked closely at this series yet...
+ /*
+ * nodeinfo-mhz should return maximum frequency,
+ * but cpu MHz of /proc/cpuinfo is scaled by power saving feature.
+ * So it gets cpufreq/cpuinfo_max_freq, if possible.
+ */
+ ret = get_cpu_value(0, cpufreq/cpuinfo_max_freq, true);
+ if (ret 0)
+ return -1;
+ else if (ret != 1) {
+ /* convert unit */
+ cpu_mhz = ret / 1000;
But which units is this converting between, and should it truncate or
round up?
I think it divide by 1000 is collect, because my machine returns below
values.
-
# cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_max_freq
231
231
231
231
231
231
231
231
# grep 'cpu MHz' /proc/cpuinfo
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
-
On the other hand, I don't have clear opinion about truncate or round up.
Present implementation of linuxNodeInfoCPUPopulate() selects truncate,
so I implement to truncate logic.
Are my explanations enough?
If not or I'm misunderstanding something, please let me know.
I think we should round up in case we request something, because then
we get at least what we requested. If we truncate a request we might
get less than we requested, this might result in a bad situation.
Recently we switched from truncation to rounding up for memory and
storage request because of this.
But here we are reporting something. In that case we should truncate,
because if we would round up we could report more than there actually
is, this might result in a bad situation too.
So with rounding up request and truncating reports we are on the safe
side in both cases.
Matthias
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Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist
Hi, Eric
On Tue, 1 Feb 2011 10:26:36 +0900
Minoru Usui u...@mxm.nes.nec.co.jp wrote:
Hi, Eric
On Mon, 31 Jan 2011 15:46:39 -0700
Eric Blake ebl...@redhat.com wrote:
On 01/27/2011 02:51 AM, Minoru Usui wrote:
virNodeGetInfo() gets from
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq, first.
Signed-off-by: Minoru Usui u...@mxm.nes.nec.co.jp
I haven't looked closely at this series yet...
+/*
+ * nodeinfo-mhz should return maximum frequency,
+ * but cpu MHz of /proc/cpuinfo is scaled by power saving feature.
+ * So it gets cpufreq/cpuinfo_max_freq, if possible.
+ */
+ret = get_cpu_value(0, cpufreq/cpuinfo_max_freq, true);
+if (ret 0)
+ return -1;
+else if (ret != 1) {
+ /* convert unit */
+ cpu_mhz = ret / 1000;
But which units is this converting between, and should it truncate or
round up?
I think it divide by 1000 is collect, because my machine returns below values.
-
# cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_max_freq
231
231
231
231
231
231
231
231
# grep 'cpu MHz' /proc/cpuinfo
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
-
On the other hand, I don't have clear opinion about truncate or round up.
Present implementation of linuxNodeInfoCPUPopulate() selects truncate,
so I implement to truncate logic.
Are my explanations enough?
If not or I'm misunderstanding something, please let me know.
--
Minoru Usui u...@mxm.nes.nec.co.jp
--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist
On 01/27/2011 02:51 AM, Minoru Usui wrote:
virNodeGetInfo() gets from
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq, first.
Signed-off-by: Minoru Usui u...@mxm.nes.nec.co.jp
I haven't looked closely at this series yet...
+/*
+ * nodeinfo-mhz should return maximum frequency,
+ * but cpu MHz of /proc/cpuinfo is scaled by power saving feature.
+ * So it gets cpufreq/cpuinfo_max_freq, if possible.
+ */
+ret = get_cpu_value(0, cpufreq/cpuinfo_max_freq, true);
+if (ret 0)
+ return -1;
+else if (ret != 1) {
+ /* convert unit */
+ cpu_mhz = ret / 1000;
But which units is this converting between, and should it truncate or
round up?
--
Eric Blake ebl...@redhat.com+1-801-349-2682
Libvirt virtualization library http://libvirt.org
signature.asc
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Re: [libvirt] [PATCH 1/2] Get cpuMhz of virNodeGetInfo() from cpufreq/cpuinfo_max_freq, if exist
Hi, Eric
On Mon, 31 Jan 2011 15:46:39 -0700
Eric Blake ebl...@redhat.com wrote:
On 01/27/2011 02:51 AM, Minoru Usui wrote:
virNodeGetInfo() gets from
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq, first.
Signed-off-by: Minoru Usui u...@mxm.nes.nec.co.jp
I haven't looked closely at this series yet...
+/*
+ * nodeinfo-mhz should return maximum frequency,
+ * but cpu MHz of /proc/cpuinfo is scaled by power saving feature.
+ * So it gets cpufreq/cpuinfo_max_freq, if possible.
+ */
+ret = get_cpu_value(0, cpufreq/cpuinfo_max_freq, true);
+if (ret 0)
+ return -1;
+else if (ret != 1) {
+ /* convert unit */
+ cpu_mhz = ret / 1000;
But which units is this converting between, and should it truncate or
round up?
I think it divide by 1000 is collect, because my machine returns below values.
-
# cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_max_freq
231
231
231
231
231
231
231
231
# grep 'cpu MHz' /proc/cpuinfo
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
cpu MHz : 2333.331
-
On the other hand, I don't have clear opinion about truncate or round up.
Present implementation of linuxNodeInfoCPUPopulate() selects truncate,
so I implement to truncate logic.
--
Minoru Usui u...@mxm.nes.nec.co.jp
--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
