On Mon, Mar 19, 2012 at 12:37 PM, Gleb Natapov <gleb@xxxxxxxxxx> wrote: > On Mon, Mar 19, 2012 at 12:20:30PM +0530, shashank rachamalla wrote: >> On Sun, Mar 18, 2012 at 10:21 PM, Gleb Natapov <gleb@xxxxxxxxxx> wrote: >> > On Sun, Mar 18, 2012 at 09:47:55PM +0530, shashank rachamalla wrote: >> >> >> I guess things are working fine with perf. But why not with oprofile ? >> >> >> >> >> > Looks like it. I never tried oprofile. Will try to reproduce your >> >> > problem and see what oprofile is doing. >> >> >> >> I am using ubuntu 10.04 with 2.6.32-21-generic kernel as guest and >> >> oprofile 0.9.6. >> >> Also, I have tried to capture kvm-events ( perf patch ) in host while >> >> running oprofile and perf in guest. >> >> Please see the attachment. I have run the tests in three cases for the >> >> around 5 secs. >> >> >> >> There are more number of MSR reads and writes in case of perf which I >> >> think is normal. However, there are very few MSR reads and writes with >> >> oprofile. Also, the number of NMI exceptions are too high in case of >> >> oprofile. >> >> >> > Which host kernel are you using? Try latest kvm.git and check if you see >> > something unusual in dmesg. >> >> Currenly running 3.3.0-rc5. will try with the latest source from kvm >> git and let you know. >> >> > Thanks, there were some fixes that didn't make it into 3.3. rdpmc > instruction emulation fix is one of them. If oprofile uses it this can > explain the problem. > I have tried with latest kvm source from git and also with 3.0 guest kernel but oprofile fails to collect any samples on guest. I am using a core2duo processor which is considered by oprofile as pentium pro model. > -- > Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
