From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takuya Yoshikawa Date: Sun, 01 Jul 2012 13:18:57 +0000 Subject: Re: [PATCH 6/6] KVM: MMU: Avoid handling same rmap_pde in kvm_handle_hva_range() Message-Id: <20120701221857.f3b9ee04e590ff7f1a0a335a@gmail.com> List-Id: References: <20120628105733.ccd9abb3.yoshikawa.takuya@oss.ntt.co.jp> <20120628110235.7410445e.yoshikawa.takuya@oss.ntt.co.jp> <4FEC9A2B.6000104@redhat.com> <20120629104629.b369cd40.yoshikawa.takuya@oss.ntt.co.jp> <4FEFFF11.4000309@redhat.com> In-Reply-To: <4FEFFF11.4000309@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Avi Kivity Cc: Takuya Yoshikawa , mtosatti@redhat.com, agraf@suse.de, paulus@samba.org, aarcange@redhat.com, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org On Sun, 01 Jul 2012 10:41:05 +0300 Avi Kivity wrote: > >> > Note: in the new code we could not use trace_kvm_age_page(), so we just > >> > dropped the point from kvm_handle_hva_range(). > >> > > >> > >> Can't it be pushed to handler()? > > > > Yes, but it will be changed to print rmap, not hva and gfn. > > I will do in the next version. > > We should try to avoid changing the tracepoint ABI. If we pass the > memslot to handler(), we should be able to reconstruct the gfn and hva. That's not enough because we only know rmapp in the handler: we also need level or something. I agree that passing memslot for keeping the ABI is good, but how about two more arguments? BTW, trace_kvm_age_page() is tracing every handler, not just kvm_age_rmapp(). Is this intentional? If we trace in the caller, in kvm_age_hva(), we know hva, but not gfn. Thanks, Takuya