I''m compiling some tarballs in both the guest domains below (fedora1
and
fedora2), they''re quite compute/cpu intensive, when I do a xm top, I
get the
following, can someone tell me what does it mean to have CPU at 98.6% on one
guest domain while 84.9% in the other when the host/domain-0 is at 3.2%? Thx
in advance.
--
xentop - 20:38:02 Xen 3.0-unstable
3 domains: 2 running, 0 blocked, 0 paused, 0 crashed, 0 dying, 0 shutdown
Mem: 1038488k total, 1028408k used, 10080k free CPUs: 2 @ 3391MHz
NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k) MAXMEM(%)
VCPUS NETS NETTX(k) NETRX(k) SSID
Domain-0 -----r 41 3.2 131100 12.6 no limit
n/a 2 8 879 378 0
fedora1 ------ 91 98.6 437652 42.1 442368 42.6
1 2 8 34 0
fedora2 -----r 60 84.9 437564 42.1 442368 42.6
1 2 7 36 0
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rickey berkeley
2006-Jul-04 13:04 UTC
[Xen-devel] Re: [Xen-users] What does xm top mean by the following:
I think we can send this also to the developing mail list.
from pv
I''m compiling some tarballs in both the guest domains below (fedora1
and
fedora2), they''re quite compute/cpu intensive, when I do a xm top, I
get the
following, can someone tell me what does it mean to have CPU at 98.6% on one
guest domain while 84.9% in the other when the host/domain-0 is at 3.2%? Thx
in advance.
--
xentop - 20:38:02 Xen 3.0-unstable
3 domains: 2 running, 0 blocked, 0 paused, 0 crashed, 0 dying, 0 shutdown
Mem: 1038488k total, 1028408k used, 10080k free CPUs: 2 @ 3391MHz
NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k) MAXMEM(%)
VCPUS NETS NETTX(k) NETRX(k) SSID
Domain-0 -----r 41 3.2 131100 12.6 no limit
n/a 2 8 879 378 0
fedora1 ------ 91 98.6 437652 42.1 442368 42.6
1 2 8 34 0
fedora2 -----r 60 84.9 437564 42.1 442368 42.6
1 2 7
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Petersson, Mats
2006-Jul-04 13:17 UTC
RE: [Xen-devel] Re: [Xen-users] What does xm top mean by the following:
________________________________ From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of rickey berkeley Sent: 04 July 2006 14:05 To: pv Cc: xen-devel@lists.xensource.com; xen-users@lists.xensource.com Subject: [Xen-devel] Re: [Xen-users] What does xm top mean by the following: I think we can send this also to the developing mail list. from pv I''m compiling some tarballs in both the guest domains below (fedora1 and fedora2), they''re quite compute/cpu intensive, when I do a xm top, I get the following, can someone tell me what does it mean to have CPU at 98.6% on one guest domain while 84.9% in the other when the host/domain-0 is at 3.2%? Thx in advance. -- xentop - 20:38:02 Xen 3.0-unstable 3 domains: 2 running, 0 blocked, 0 paused, 0 crashed, 0 dying, 0 shutdown Mem: 1038488k total, 1028408k used, 10080k free CPUs: 2 @ 3391MHz NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k) MAXMEM(%) VCPUS NETS NETTX(k) NETRX(k) SSID Domain-0 -----r 41 3.2 131100 12.6 no limit n/a 2 8 879 378 0 fedora1 ------ 91 98.6 437652 42.1 442368 42.6 1 2 8 34 0 fedora2 -----r 60 84.9 437564 42.1 442368 42.6 1 2 7 Are you asking "Where does the rest of the CPU time (out of 200%) go?" Then I can give you a rough answer: It is "lost" in the Hypervisor... It''s probably used up in part to handle the disk accesses that your compile will do. Interrupts are passed through the hypervisor, as does page-fault handling and a few other processor exceptions. I doubt that the time spent dealing with for example page-faults is accounted in the correct domain (and it may not be accounted at all). If this is not what you were asking, please clarify what your question is... -- Mats _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Thx Mats - I''m not quite sure what the %-ages mean i.e. what is 100% - is it the sum of all the cpu(hw or hyperthreaded or vcpus) on all the domains? Take for .e.g a data center utilizing 35% of CPU for a particular server; And, enter Xen: and you have installed 2 instead of one server running on the same h/w w/ the hope of increasing utilization. So, instead of 35%, one is expected to see 35%+x afa utilization (is this true?) It does not matter what base-line or metrics one is presented with (I''m happy w/ the top presentation); as long as it is clear and easy to explain to a ''CIO, CFO or VP-finance or an unsuspecting fellow-worker'' - if you know what I mean, I''ll look forward to some documentation or an explanation to this regard. Thx in advance. -- On 7/1/06, pv <vishnubhatt@gmail.com> wrote:> > I''m compiling some tarballs in both the guest domains below (fedora1 and > fedora2), they''re quite compute/cpu intensive, when I do a xm top, I get the > following, can someone tell me what does it mean to have CPU at 98.6% on > one guest domain while 84.9% in the other when the host/domain-0 is at > 3.2%? Thx in advance. > > -- > xentop - 20:38:02 Xen 3.0-unstable > 3 domains: 2 running, 0 blocked, 0 paused, 0 crashed, 0 dying, 0 shutdown > Mem: 1038488k total, 1028408k used, 10080k free CPUs: 2 @ 3391MHz > NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k) MAXMEM(%) > VCPUS NETS NETTX(k) NETRX(k) SSID > Domain-0 -----r 41 3.2 131100 12.6 no limit > n/a 2 8 879 378 0 > fedora1 ------ 91 98.6 437652 42.1 442368 42.6 > 1 2 8 34 0 > fedora2 -----r 60 84.9 437564 42.1 442368 42.6 > 1 2 7 36 0 > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Petersson, Mats
2006-Jul-05 10:03 UTC
RE: [Xen-users] Re: What does xm top mean by the following:
One CPU will be able to give 100%, so 200% would be the result of 2 cpu''s [which can also be seen by you having 2 domains running - you can only have one domain per CPU at any given time]. A CPU in this context is either anything the OS considers a CPU, which means hyperthreaded "virtual" CPU''s are counted, just like cores on a dual core CPU. If you have one socket with two cores, which have hyperthreading, the OS will see it as 4 CPU''s. In my test-system, I''ve got two dual core processors, and Xen sees that as 4 CPU''s [I work for AMD, we don''t do HyperThreading - as we have shorter pipelines...]. If you take one server using 35% of one CPU, and move it to a Xen-system, that domain would use 35% + x% of Hypervisor time - because we''re now administering the domain through Xen, which means a little bit of extra work [or in extreme cases, quite a bit of extra work - depends entirely on the domain]. And as I said earlier, the processor(s) may well work 100% of the time, but the total in Xen-top isn''t quite adding up to 100% * cpu_count, because some time is "lost". I don''t know this for sure, but I''ve seen it before in other systems - some time isn''t counted anywhere, although work is done... -- Mats ________________________________ From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of pv Sent: 05 July 2006 00:04 To: xen-users Subject: [Xen-users] Re: What does xm top mean by the following: Thx Mats - I''m not quite sure what the %-ages mean i.e. what is 100% - is it the sum of all the cpu(hw or hyperthreaded or vcpus) on all the domains? Take for .e.g a data center utilizing 35% of CPU for a particular server; And, enter Xen: and you have installed 2 instead of one server running on the same h/w w/ the hope of increasing utilization. So, instead of 35%, one is expected to see 35%+x afa utilization (is this true?) It does not matter what base-line or metrics one is presented with (I''m happy w/ the top presentation); as long as it is clear and easy to explain to a ''CIO, CFO or VP-finance or an unsuspecting fellow-worker'' - if you know what I mean, I''ll look forward to some documentation or an explanation to this regard. Thx in advance. -- On 7/1/06, pv <vishnubhatt@gmail.com> wrote: I''m compiling some tarballs in both the guest domains below (fedora1 and fedora2), they''re quite compute/cpu intensive, when I do a xm top, I get the following, can someone tell me what does it mean to have CPU at 98.6% on one guest domain while 84.9% in the other when the host/domain-0 is at 3.2%? Thx in advance. -- xentop - 20:38:02 Xen 3.0-unstable 3 domains: 2 running, 0 blocked, 0 paused, 0 crashed, 0 dying, 0 shutdown Mem: 1038488k total, 1028408k used, 10080k free CPUs: 2 @ 3391MHz NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k) MAXMEM(%) VCPUS NETS NETTX(k) NETRX(k) SSID Domain-0 -----r 41 3.2 131100 12.6 no limit n/a 2 8 879 378 0 fedora1 ------ 91 98.6 437652 42.1 442368 42.6 1 2 8 34 0 fedora2 -----r 60 84.9 437564 42.1 442368 42.6 1 2 7 36 0 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users