On 03/21/2011 06:16 PM, Ben Nagy wrote:
>> On Mon, Mar 21, 2011 at 7:38 PM, Avi Kivity<avi@xxxxxxxxxx> wrote:
>> > In the future, please post the binary perf.dat.
>>
>> Hi Avi,
>>
>> How do I do that?
>
> 'make nconfig' and go to the kernel hacking section.
Imprecise question sorry, I meant how do I get the perf.dat not how do
I disable the debugging.
'perf record' dumps perf.dat in the current directory.
On the non-debug kernel: Linux eax 2.6.38-7-server #36-Ubuntu SMP Fri
Mar 18 23:36:13 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
150512.00 67.8% __ticket_spin_lock
[kernel.kallsyms]
11126.00 5.0% memcmp_pages
[kernel.kallsyms]
9563.00 4.3% native_safe_halt
[kernel.kallsyms]
8965.00 4.0% svm_vcpu_run
/lib/modules/2.6.38-7-server/kernel/arch/x86/kvm/kvm-amd.ko
6489.00 2.9% tg_load_down
[kernel.kallsyms]
4676.00 2.1% kvm_get_cs_db_l_bits
/lib/modules/2.6.38-7-server/kernel/arch/x86/kvm/kvm.ko
1931.00 0.9% load_balance_fair
[kernel.kallsyms]
1917.00 0.9% ktime_get
[kernel.kallsyms]
1624.00 0.7% walk_tg_tree.clone.129
[kernel.kallsyms]
1542.00 0.7% find_busiest_group
[kernel.kallsyms]
1326.00 0.6% find_next_bit
[kernel.kallsyms]
673.00 0.3% lock_hrtimer_base.clone.25
[kernel.kallsyms]
624.00 0.3% copy_user_generic_string [kernel.kallsyms]
top now says:
top - 00:11:35 up 22 min, 4 users, load average: 0.11, 6.15, 7.78
Tasks: 491 total, 3 running, 488 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.9%us, 15.4%sy, 0.0%ni, 83.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 99068660k total, 70831760k used, 28236900k free, 10036k buffers
Swap: 2438140k total, 2173652k used, 264488k free, 3396144k cached
With average 'resting cpu' per idle guest 8%, 96 guests running.
Is this as good as I am going to get? It seems like I can't really
debug that lock contention without blowing stuff up because of the
load of the lock debugging...
Post perf.dat for the non-debug kernel, and we'll see. You're probably
hitting some Linux scaling limit, and these are continuously expanded as
big hardware becomes more common.
--
error compiling committee.c: too many arguments to function
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