RE: [Xen-devel] RE: [PATCH] Xenoprof passive domain support fixes

["Santos, Jose Renato G" <joserenato.santos@xxxxxx>]

>> -----Original Message-----
>> From: Ray Bryant [mailto:raybry@xxxxxxxxxxxxxxxxx] 
>> Sent: Wednesday, July 12, 2006 11:40 AM
>> To: Santos, Jose Renato G
>> Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Yang, Xiaowei
>> Subject: Re: [Xen-devel] RE: [PATCH] Xenoprof passive domain 
>> support fixes
>> 
>> Hi Renato,
>> 
>> On Tuesday 11 July 2006 15:51, Santos, Jose Renato G wrote:
>> >  Ray,
>> >
>> <snip>
>> 
>> > >> Additionally, I find that "opreport -lx" will report 
>> "no symbols" 

Ray,

I did not notice at the first time that you were using option -x on
opreport. According to opreport man page this option should not be
used in you did not run opcontrol with --separate option. I am not sure
what the behavior would be in this case, but that is what may be causing
the kernel samples to be ommited. Try running opreport without the -x
option.

Thanks for porting the patch to oprofile 0.9.1. I am fixing a few things
and plan to post a new version for 0.9.1 in a few days.

Renato

>> > >> for
>> > >> papps*-syms:
>> > >>
>> > >> samples  %        app name                 symbol name
>> > >> 76273    23.7738  papps2-syms              (no symbols)
>> > >> 19131     5.9630  pxen2-syms               l2e_rw_fault
>> > >> 17278     5.3854  jbd                      (no symbols)
>> > >> 12228     3.8114  ext3                     (no symbols)
>> > >> 11840     3.6905  libc-2.4.so              vfprintf
>> > >> 10256     3.1967  libc-2.4.so
>> > >> _IO_file_xsputn@@GLIBC_2.2.5
>> > >> 8587      2.6765  xen-syms                 general_protection
>> > >> 7374      2.2984  pxen2-syms               
>> vmx_asm_vmexit_handler
>> > >> 5212      1.6245  pxen2-syms               resync_all
>> > >> 5128      1.5984  xen-syms                 write_cr3
>> > >> <snip>
>> > >>
>> > >> unless I do an "ln -s /boot/vmlinux2-syms 
>> /boot/papps2-syms".  (It 
>> > >> appears that opreport should be creating papps2-syms instead of 
>> > >> vmlinux2-syms??)
>> >
>> > papps2-syms represent samples collected in user level for 
>> domain2 (i.e.
>> > ring 3). Remember that passive domain profiling cannot decode 
>> > application level samples since domain0 does not know the current 
>> > memory mappings of user level processes in domain 2. 
>> Therefore it is 
>> > expected that opreport will report "no symbols" for papps2-syms.
>> >
>> 
>> I see.  Oops.  :-)
>> 
>> > What is suspicious to me is that opreport is not reporting 
>> any samples 
>> > in the kernel for domain2 (they should have appeared under the name
>> > vmlinux2-syms)
>> 
>> Perhaps you meant pvmlinux2-syms here?
>> 
>> > This is probably a bug. Maybe this is triggered if you do 
>> not specify 
>> > the option --passive-images. Did you specify this option? 
>> If not, try 
>> > running the command with --passive-images=<linux image 
>> file for xenU> 
>> > (e.g. --passive-images=/boot/vmlinux-syms-2.6.16-xenU)
>> >
>> 
>> Yes, here is the setup script:
>> 
>> opcontrol 
>> --vmlinux=/home/raybry/xenbits-unstable.$cs.hg/linux-2.6.16.1
>> 3-xen/vmlinux
>> opcontrol --start-daemon --active-domains=0 
>> --passive-domains=$passive \
>>         --passive-images=/home/raybry/RH4U2/vmlinux  \
>>         --xen=/home/raybry/xenbits-unstable.$cs.hg/xen/xen-syms \
>>         --verbose=all --event=GLOBAL_POWER_EVENTS:100000:1:1:1
>> 
>> where $cs is the current change set I am running and 
>> $passive is the passive domain id.
>> 
>> Of course, the actual image file for an HVM guest is stored 
>> in the / file system of the
>> guest, which in this case is a loopback mounted file.   So 
>> the vmlinux referenced above
>> is a copy of that file in the host's file system.
>> 
>> There are no samples attributed to pvmlinux2-syms in the 
>> oprofiled.log.   There are
>> lots of samples attributed to papps2-syms.   
>> 
>> Now this is all with your patches applied to change set 
>> 10428.  It's possible, I suppose, that there are some subtle 
>> differences making this incorrect at that change set level.
>> I'll move up to a more recent change set and try again.  
>> Also, I "ported" your oprofile changes forward to 0.9.1, so 
>> I could have messed that up.  See the message I sent to 
>> Markus on xen-devel for a copy of my version of your 
>> 
>> > >> Finally, I'm not convinced yet that the sample reports 
>> for the HVM 
>> > >> guest (papps2-syms or pvmlinux2-syms, in this case) are 
>> correct.  
>> > >> I'm going to run some native and xen profile sessions using the 
>> > >> same benchmark and see if I can correlate the results at all.
>> >
>> >  There is a problem with the current version of xenoprof 
>> for passive 
>> > domains. Samples are being assigned to wrong samples. I 
>> posted a patch 
>> > last week, that fix this problem but it seems that it was 
>> not pushed 
>> > into the main unstable tree yet.
>> > Try applying that patch and check if they match what you get from 
>> > native.
>> > (If you cannot find the patch, please let me know I will 
>> forward it to
>> > you)
>> > I would appreciate if you could send me the results of your tests, 
>> > either if you find problems or if they are successfull. I 
>> think not 
>> > many people have used passive domain support yet, and any feedback 
>> > would be usefull.
>> 
>> I am running with your patches from 2006-07-07 3:15:15 for 
>> both xen and oprofile.
>> However, as stated above, I am running under changeset 
>> 10428.   Let me upgrade 
>> and try again.
>> 
>> >
>> > Thanks
>> >
>> > Renato
>> 
>> Thank you!
>> 
>> Best Regards,
>> --
>> Ray Bryant
>> AMD Performance Labs                   Austin, Tx
>> 512-602-0038 (o)                 512-507-7807 (c)
>> 
>> 
>> 

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