From: Santos, J. R. G (J. R. Santos) <jos...@hp...> - 2005-04-12 06:35:59
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Oh, I forgot to answer your question on Xen Xen uses the term "domain" to refer to a "virtual machine" Renato > -----Original Message----- > From: Santos, Jose Renato G (Jose Renato Santos)=20 > Sent: Monday, April 11, 2005 11:32 PM > To: 'John Levon' > Cc: oprofile-list; Aravind Menon; G John Janakiraman; Turner, Yoshio > Subject: RE: [Xen-devel] [PATCH] Xenoprof: Enabling=20 > performance profiling in Xen >=20 >=20 >=20 > John, >=20 > I am sorry you received this out of context. > I was planing to send you a note describing our work=20 > on enabling oprofile on the Xen virtual machine, but=20 > the discussion on the Xen mailing list was forwarded > to the OProfile list, before I had a chance to > send you some information. >=20 > Xen is an open source virtual machine monitor. > While Vmware provides full virtualization where the OS > believes is running on a physical machine, Xen provides > paravirtualization. With paravirtualization, the OS > is modified and made aware of the virtualization layer. > This reduces the overhead of hardware emulation and improve > system performance >=20 > Before our work, it was not possile to use Oprofile in > systems running Xen. > Our group at HP Labs modified Oprofile and Xen to enable > statistical profiling in Xen. Most of the code was written > by Aravind Menon while working in our group.=20 > =20 > At a high level, we moved the X86 low level (hardware dependent) > Oprofile component into the Xen hypervisor and exposed > access to this functionality through a new hypercall > (equivalent of system call at the Virtual machine layer). > We then created a Xen specific low level driver for Oprofile > which instead of programming the performance counters directly > uses this new hypercall. >=20 > I have attached the three patches that are needed, one for the > Xen hypervisor, one for the linux kernel and one for the user > level Oprofile code. The patch for the the linux code was=20 > created for the Xen variation of linux 2.6.10 (commonly > called xenolinux). This is linux with the modifications > necessary for making the OS aware of the virtualization layer. > Therefore, the patches would not apply cleanly to standard > linux 2.6. >=20 > We would be very interested in knowing your thoughts on this > and if you would be interestd in incorporating this > on the main oprofile distribution. >=20 > Thanks >=20 > Renato >=20 >=20 >=20 > > -----Original Message----- > > From: John Levon [mailto:mo...@co...] On Behalf Of > > John Levon > > Sent: Monday, April 11, 2005 4:12 PM > > To: Santos, Jose Renato G (Jose Renato Santos) > > Cc: William Cohen; xen...@li...;=20 > > oprofile-list; Aravind Menon; G John Janakiraman; Turner, Yoshio > > Subject: Re: [Xen-devel] [PATCH] Xenoprof: Enabling=20 > > performance profiling in Xen > >=20 > >=20 > > On Mon, Apr 11, 2005 at 03:37:57PM -0700, Santos, Jose Renato > > G (Jose Renato Santos) wrote: > >=20 > > >=20 > >=20 > http://lists.xensource.com/archives/html/xen-devel/2005-04/msg00256.ht > > > ml > >=20 > > Where can I get the diff against oprofile userspace source, > > plus a diff of the changes to the kernel driver? > >=20 > > (It'd be really handy if somebody wrote up a little bit about > > Xen (no idea what a domain is) for us OProfile people too) > >=20 > > regards > > john > >=20 >=20 |