From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v2 5/7] KVM: Introduce PV kick in flush tlb Date: Tue, 3 Jul 2012 05:07:13 -0300 Message-ID: <20120703080713.GA12579@amt.cnet> References: <20120604050223.4560.2874.stgit@abhimanyu.in.ibm.com> <20120604050755.4560.24727.stgit@abhimanyu.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: peterz@infradead.org, mingo@elte.hu, avi@redhat.com, raghukt@linux.vnet.ibm.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, jeremy@goop.org, vatsa@linux.vnet.ibm.com, hpa@zytor.com To: "Nikunj A. Dadhania" Return-path: Content-Disposition: inline In-Reply-To: <20120604050755.4560.24727.stgit@abhimanyu.in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Mon, Jun 04, 2012 at 10:38:17AM +0530, Nikunj A. Dadhania wrote: > In place of looping continuously introduce a halt if we do not succeed > after some time. > > For vcpus that were running an IPI is sent. In case, it went to sleep > between this, we will be doing flush_on_enter(harmless). But as a > flush IPI was already sent, that will be processed in ipi handler, > this might result into something undesireable, i.e. It might clear the > flush_mask of a new request. > > So after sending an IPI and waiting for a while, do a halt and wait > for a kick from the last vcpu. > > Signed-off-by: Srivatsa Vaddagiri > Signed-off-by: Nikunj A. Dadhania Again, was it determined that this is necessary from data of benchmarking on the in-guest-mode/out-guest-mode patch?