RE: [Xen-devel] RE: [PATCH] Xenoprof passive domain support fixes
>> -----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,
>> > >> Additionally, I find that "opreport -lx" will report
>> "no symbols"
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
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.
>> > >> 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
>> > >> 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 --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
>> > >> 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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